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Out-of-This-World Medical Devices Inspired by Space

The 50th anniversary of Apollo 11’s moon landing has got us thinking about the wonders of space—including medical devices and diagnostics that have evolved from NASA research and other space missions. Technologies have to be robust to withstand the rigors of space.  Here are some extraordinary accomplishments that have helped advance medicine here on Earth.

Electronic skin could outperform its human counterpart

Electronic skin could outperform its human counterpart

If you’re receptive to theories about robots eventually making humans redundant, here’s a little something to elevate your paranoia: Researchers in Singapore have developed electronic skin with a sense of touch that could respond faster to stimuli than human skin. In addition to boosting a robot’s ability to feel objects and adapt accordingly, the Asynchronous Coded Electronic Skin (ACES) developed by National University of Singapore (NUS) scientists could also improve the performance of prosthetic devices. But you knew they would say that to lull us into a sense of complacency, right?

“Humans use our sense of touch to accomplish almost every daily task, such as picking up a cup of coffee or making a handshake. Without it, we will even lose our sense of balance when walking,” explained Assistant Professor Benjamin Tee from NUS Materials Science and Engineering. “Similarly, robots need to have a sense of touch in order to interact better with humans, but robots today still cannot feel objects very well,” said Tee, who has been working on electronic skin technologies for more than a decade in hopes of giving robots and prosthetic devices a better sense of touch.

Assistant Professor Tee and fellow researchers at National University of Singapore
Assistant Professor Benjamin Tee (left) and his team from Materials Science and Engineering at the National University of Singapore.

Tee and his team spent a year and a half developing a sensor system that detects signals in a manner similar to the human sensor nervous system. Unlike the nerve bundles in the human skin, however, the ACES system is made up of a network of sensors connected via a single electrical conductor. Moreover, it deviates from existing electronic skins that have interlinked wiring systems, making them sensitive to damage and difficult to scale up.

ACES can detect touches more than 1,000 times faster than the human sensory nervous system, according to the researchers. For example, it is capable of differentiating physical contact between different sensors in less than 60 nanoseconds—the fastest time ever achieved by an electronic skin technology—even with large numbers of sensors. ACES-enabled skin can accurately identify the shape, texture and hardness of objects within 10 milliseconds, ten times faster than the blinking of an eye.

The ACES platform also is more robust than existing artificial systems. Unlike current systems used to interconnect sensors in electronic skins, all the sensors in ACES can be connected to a common electrical conductor, with each sensor operating independently, explained a press release on the NUS website. This allows ACES-enabled electronic skin to continue functioning as long as there is one connection between the sensor and the conductor, making it less vulnerable to damage.

But what if the skin, despite everything, sustains some damage? Tee has a solution to that, as well. By pairing ACES with a transparent, self-healing and water-resistant sensor skin layer, also developed by Tee and his team, the electronic skin can self-repair, just like human skin, writes Verdict Medical Devices, reporting on Tee’s research.

“One of the challenges with many self-healing materials today is that they are not transparent and they do not work efficiently when wet,” said Tee, as reported by Verdict Medical Devices. “With this idea in mind, we began to look at jellyfish—they are transparent, and able to sense the wet environment. So, we wondered how we could make an artificial material that could mimic the water-resistant nature of jellyfish and yet also be touch-sensitive."

The self-healing skin works by suspending a fluorocarbon-based polymer in a fluorine-rich ionic liquid to create a gel. The polymer network interacts with the ionic liquid via reversible ion-dipole interactions, which allows it to self-heal, reported Verdict Medical Devices.

ACES technology can be used to develop prosthetic limbs that will help disabled individuals better restore their sense of touch, said Tee. Other potential applications include developing more intelligent robots that can perform disaster recovery tasks or take over mundane packaging operations, for example. The NUS team is looking to further apply the ACES platform on advanced robots and prosthetic devices in the next phase of its research.

The research was first reported in the scientific journal Science Robotics published on July 17, 2019.

Zoll Gains Interactive Trauma and First Aid Systems Through New Acquisition

Businesswire Zoll Gains Interactive Trauma and First Aid Systems Through New Acquisition

Zoll Medical said it has acquired “substantially” all of the assets of Mobilize RRS, a company that develops interactive trauma and first aid systems. The companies did not disclose the sum.

The Pittsford, NY-based company markets the Mobilize Rescue Systems app and associated rescue kits.

Since the average ambulance response time is around seven to fifteen minutes, a bystander is frequently a victim's best hope for survival. However, bystanders don't always have the knowledge or equipment they need to intervene. There is a universal need to help bystanders play a more active role in responding to emergencies that result from accidents, medical emergencies, and acts of violence.

“Zoll is a leader in providing high-quality AEDs to help people save the life of someone suffering from sudden cardiac arrest,” Elijah White, President of Zoll Resuscitation, said in a release. “Mobilize Rescue Systems are a natural extension for Zoll, in that they give people the ability to help victims of nearly every type of emergency.”

The Mobilize RRS deal comes on the heels of Zoll acquiring TherOx for an undisclosed sum. Irvine, CA-based TherOX is focused on improving the treatment of acute myocardial infarction, and sells systems to deliver SuperSaturated Oxygen (SSO2) Therapy. In April, FDA greenlit the SSO2 therapy.

Designing a Drug-Delivery Device? Read This First

Designing a Drug-Delivery Device? Read This First
Figure 1 shows a schematic diagram of the syringe system in which needle is pre-attached to the syringe barrel at frontend. This configuration is also called a syringe with a staked needle. The syringe barrel or container is called a primary container as it holds the medicine and has direct contact with it. The needle has two open ends and one of it will remain inside the syringe barrel. The needle is made out of metal and comes in different gauges. The needle gauge is defined by its inner bore diameter, outer diameter, and wall thickness. There are other syringe configurations in which needles can be attached at the front end of the syringe manually before the injection. The syringe barrel is filled with the drug fluid or medicine. The rubber stopper is placed inside the syringe barrel at the other end so that fluid will always remain inside the syringe barrel. The fluid will not come out of the needle unless there is an adequate amount of force is applied on the rubber stopper through the plunger rod to move it towards needle end. The plunger rod may be attached to the rubber stopper as shown.

In pharmaceutical industries, medicines are developed to treat certain illnesses. There are several types of delivery systems with which these medicines can be administered into the human or animal body. Injectable medicines are mainly administered with the help of syringes or delivery devices. Syringes or delivery devices are used with needles to inject the medicine or drug into the body.

However, a major challenge is to develop the syringe or delivery device which can be used to deliver the drug under the skin with more comfort and less pain. Injecting the drug under the skin with the help of syringes is mostly dependent upon the fluid properties of the drug. The design of delivery devices or syringes is based on fluid properties of the medicine or drug. It becomes more inconvenient or painful to the patient if the drug or fluid is with high viscosity or semi-solid type which needs high force to inject.

So, it is very important to understand the pressure and force requirement for delivery of highly viscous fluid. Based on the force requirement to deliver the drug, the device designer can design and develop a delivery system which would be used by the patient or user with more comfort and less pain. For the measurement of force, injectable drugs or fluids are classified as Newtonian and non-Newtonian fluids. The information in this paper on a mathematical equation, experiments, and suggestions will help the pharmaceutical industries as a basis to design and develop the syringes or drug delivery devices to deliver highly viscous, semi-solid or visco-elastic type of drug or medicine. The design parameters or functional features of the drug delivery device can be collectively called as design formulation. So, for a drug-device combination product, both the things viz. design and drug formulations are equally important for its safety and efficacy.

The material of construction (MOC) of the syringe barrel could be glass or plastic or metal. There are different types of plastics used for syringe barrel. In all cases, the inner surface of the syringe barrel should be smooth enough so that movement of rubber stopper becomes uniform and with minimum or negligible friction. The inner surface of the syringe barrel can be siliconized to make a smooth or frictionless movement of the rubber stopper inside it.

To administer the dose, the user has to insert the needle under the skin at the injection site of the body and then push the plunger rod forward to dispense the medicine. An adequate amount of force is required to push the plunger rod forward. It becomes uncomfortable and inconvenient to the patient or user if the force required to push the rubber stopper is more.

However, the needle insertion and drug delivery steps can be made automatic with the help of an auto-injector delivery device. To design an auto-injector or prefilled syringe, the designer needs to understand the force or pressure required to dispense the medicine out of the needle.

To administer the medicine with comfort and less pain, it is very important to understand the design parameters or factors of a delivery device as well as fluid properties of drug which affect the force required to push the rubber stopper forward. The force required to inject medicine at a specific flow rate with a specific needle length and the gauge is called syringeability. 

The volumetric flow through the needle is governed by the Hagen-Poiseuille equation¹:
  1.  Inner diameter of the syringe (cross-sectional area of the syringe or cartridge that holds liquid medicine)
  2. Length of the needle or needle extension
  3. Inner bore diameter of the needle
  4. Volumetric flow rate of the fluid or medicine
  5. Dynamic viscosity of the fluid or medicine

Tissue resistance to the needle at the beginning of the needle insertion and frictional force inside syringe and needle barrel also adds to the total force required. The designer can build the mathematical model based on the equation on the right. It will provide indicative value for the force required to dispense the drug out of the needle and help the designer optimize the design attributes of the delivery device.

Design constant also needs to be considered for robustness, safety, and reliability of the device. There are certain constraints on the selection of larger needle sizes and length as pain increases if the needle diameter and length increases.

The force required to push the rubber stopper from its initial position is termed as break out or initiating force and force required to keep the rubber stopper moving is called glide or sustaining force2.

Fluid Types and Experimentation

1. Newtonian Fluid3

Newtonian fluid is the fluid in which viscous stresses are linearly proportional to the local strain rate. In a Newtonian fluid, the relation between the shear stress and the shear strain is linear.

The chart below the mean break out and glide force values for the syringe filled with liquid medicine or drug formulation which has a density of 1.06gm/mL and viscosity around 2cP. The test was conducted at standard speed 50mm/min on a universal testing machine.

The volumetric flow rate or the speed at which liquid medicine needs to be delivered is important when the patient or user desires to have a full dose of a certain amount of medicine in a specified time limit. Generally, every patient wants to have a full dose within a few seconds to avoid pain and inconvenience holding a needle inside the skin. However, while doing the experiments it has been observed that if the delivery speed increases significantly, such as more than 360 mm/min, the force does not get increased in that proportion.

These tests were conducted using a primary container of 1mL long glass prefilled syringe of ISO standard with staked needles of 26 and 27Gauge. The prefilled syringe inner diameter was 6.35mm. As there is a minor difference between two needles in terms of inner bore diameter (0.26 and 0.21mm) and needle extension (15.8 and 12.7mm), break out and glide force values also shows minor differences.

Chart 1 below also shows that the breakout and glide force mean values for other experimentation where it was observed that force to dispense liquid medicine increases significantly if the inner diameter of the primary container increases significantly keeping the viscosity of fluid same. The test was conducted on a universal testing machine with the speed of 50mm/min using the 3mL ISO standard cartridge with inner diameter 9.70mm. The needle size was 31G with 5mm needle extension. The mean breakout and glide force were 10.5 N and 8.7 N respectively.

The experiments were carried out dispensing medicine into the air and not under the skin of the patient. The breakout force graphs show that the volumetric flow somewhat follows the Hagen-Poiseuille equation at the standard delivery speed of 50 mm/min. As mentioned earlier, it is to be noted that the Hagen-Poiseuille equation will provide an indicative value of force required to dispense the drug out of the needle.

There are other factors which also influences the dispensing force. With these practical experimentations, the designer will get actual values of force required to dispense the drug. Based on these values designer can optimize design formulation by choosing the primary container system, the size, and length of the needle, the amount of drug to be delivered, time in which the dose has to be delivered.

The designer also needs to consider the stability or variability of fluid or medicine properties (viscosity and density) over the period of shelf life of the drug and optimize the design formulation accordingly. With these type of experiments and data on breakout and glide force, the designer can build a drug delivery device that will be easy to operate and less painful and more convenient to the patient. This drug delivery device could be pre-filled syringe itself or self-administrable mechanical or electromechanical pen or auto-injector.

Currently, several pharmaceutical sectors have such type of delivery devices for liquid injectable drug delivery. These devices are also available as a standard ready-to-use platform from several device manufacturers.

Challenges come in drug delivery device design when the medicine is non-Newtonian fluid like visco-elastic gel or semi-solid type of formulation.

2. Non-Newtonian Fluid

Non-Newtonian fluid4 is the fluid in which the viscosity is dependent on the shear rate. In non-Newtonian fluid, the relation between the shear stress and the shear rate is different and can even be time-dependent.

Chart 3 below shows the needle gauge versus the amount of semi-solid type drug delivered. Force applied was 55N to deliver visco-elastic semisolid gel medicine with a density of 1.05gm/mL and flow point 2500 Pa and Yield point 1900 Pa when measured using oscillation rheology at a constant angular frequency and variable shear strength at room temperature. The test was conducted at 30 mm/min speed on a universal testing machine. The prefilled syringe inner diameter was 6.35mm. The time between drug delivery start and end without stoppage was 4 seconds. After 4 seconds, there was no continuous drug delivery observed from any needle.

The semi-solid type of medicine is very difficult to deliver from the needles of higher gauges (lesser inner bore diameter). The chart below also shows there is no medicine delivered from 26G and 27G needle even after applying 55N of force on rubber stopper. It shows that lesser the needle gauge higher the weight of drug delivered. The length of the needle is important because, for the shorter length, drug delivery becomes easy.

Chart 2

It has been observed that the fluid coming out of the needle was in the form of a coil. It takes some time to form the fluid into the shape of a coil. The diameter of this coil is in line with the inner bore diameter of the needle.

Chart 3  shows the needle gauge versus force required to dispense the semi-solid type of medicine at 255mm/min. The medicine or drug used was having similar fluid properties which were used for experimentation in the above-mentioned test of Chart 2.

The inner diameter of the syringe barrel was 2.8mm. Speed was derived to deliver a certain amount of medicine in less than 10 seconds. It shows that the average force required to dispense semi-solid type medicine is directly proportional to needle gauge if needle extension, fluid properties, flow rate, and syringe inner diameter remains constant. The higher the needle gauge more would be the dispensing force required. This type of experimentation will help to optimize the design parameters of the drug delivery device.

Chart 3

After doing experiments with several combinations of needle gauges and length of the needle, it has been observed that the force required to dispense the semisolid visco-elastic gel type fluid is largely dependent on below parameters.

  1. Inner diameter of the syringe barrel
  2. Length of the needle
  3. Inner bore diameter of the needle
  4. Viscosity of the fluid or medicine

The force required to dispense the medicine is directly proportional to inner diameter of the syringe barrel and length of the needle and inversely proportional to inner diameter of the needle.

Problem Statement:

 So, the challenge here is to design prefilled syringe or drug delivery device for delivery of semi-solid viscoelastic gel type of medicine or formulation. Prefilled syringe or delivery device should be easy to use and injection should be less painful to the patient.

Solution:

While designing the drug delivery device, there are two sub-systems needs to be taken into consideration. One is the primary container system, which directly comes in contact with the drug formulation. The other is the injection, delivery, and needle retraction mechanism. The latter part can be made either manual or automatic. The objective of the primary container system is to hold the drug or medicine in the required conditions and while doing this there should not be any deter-rioting effect of it on the medicine during its shelf life. The objective of injection, delivery and needle retraction mechanism is to deliver the medicine at appropriate depth under the skin in the appropriate time with the appropriate quantity with comfort and convenience.

The force required to dispense the medicine plays a very important role in the usability of the device and comfort of the patient while administering the drug. If the force required and time taken to dispense the medicine is very high then the user feels uncomfortable with the delivery device. It also becomes painful to the user. It is more relevant in semi-solid visco-elastic gel type of medicine or formulation. To make the drug delivery device or prefilled syringe more user-friendly and with less painful to the user, the designer should optimize the delivery device or prefilled syringe design on the below parameters.

  1. Select the needle gauge and length based on the injection depth, volume to be dispensed and time required to dispense it. For example, if the needle is 21G then insertion pain would be higher as compared to 23G however the time taken to dispense the same amount of medicine would be less. Needle length is based on whether the required injection is subcutaneous or intramuscular. If the medicine is liquid the needle gauge could be much higher, like in the range of 29 to 31G and even more, if the injection is subcutaneous.
  2. The syringe barrel inner diameter should be as minimum as possible so that the force required to push the rubber stopper forward would be minimum. However, there are some constraints for the minimum inner diameter of the syringe and those are based on the strength and material of plunger rod which is used to push the rubber stopper forward.
  3. The inner shape of the syringe should be in such a way that the semi-solid fluid can move forward smoothly particularly at the neck part of the syringe where needle and syringe assembly starts. Smooth and well-optimized converging ends will help the medicine to move forward with less friction.
  4. The flanges or the neck portion of the syringe should withstand the high forces. If the designer builds the pen or an auto-injector device to deliver the drug then the primary container will be held at its neck or flanges.
  5. The plunger rod design should be in such a way that it can transfer adequate force on the rubber stopper. It should have enough strength to withstand such high force.
  6. The above five parameters are helpful while designing prefilled syringe for delivery of semi-solid visco-elastic gel type of fluid with manual needle insertion, drug delivery, and needle retraction. For automatic needle insertion and drug delivery of a semi-solid visco-elastic gel type of fluid, the delivery mechanism could be based on spring or gear or gas-driven technology. If the force required pushing rubber stopper forward and time required to dispense the desired dose is high, it is good to evaluate gear or rack and pinion mechanism.
  7. The applicable ISO6 7 8  standards and regulatory guidance9 10  have to be referred and followed while designing customized prefilled syringe as well as a delivery device. Prefilled syringe or drug delivery device performance standards are well established and the designer has to follow these guidelines and optimize the design parameters accordingly.

The injectable drug delivery by prefilled syringe or delivery device is based on the fluid properties of the medicine. If the fluid is of Newtonian type, then the force required to dispense the medicine is considerably low. The delivery of low viscosity medicine may not become inconvenient to the user or patient. However, if the fluid is of non-Newtonian in nature, there would be a considerable increase in force to dispense the medicine which in turn will increase efforts as well as pain in the delivery of the medicine.

To reduce the discomfort and increase the user-friendliness of the delivery system, it is important to consider the design factors or parameters which plays an important role in designing the delivery device. Device designer can optimize the design by selecting appropriate needle gauge and length, the inner diameter of the syringe barrel (primary container system), time and volume of fluid to be dispensed. This optimized design parameters of the delivery device can be called design formulation. With due consideration of prefilled syringe or drug delivery device design formulation, the designer can build the system that would be more convenient for the user or patient. At the same time, the designer has to consider the applicable ISO standards or regulatory guidance while finalizing the device design parameters.

References:

  1. Injecting Highly Viscous Drugs, Nov 02, 2014 By Andy Fry, Pharmaceutical Technology, Volume 38, Issue 11
  2. ISO 11608 –  3 –  Pen Injectors for medical use –  Finished cartridges –  Requirements and test methods
  3. Panton, Ronald L. (2013). Incompressible Flow (Fourth ed.). Hoboken: John Wiley & Sons. p. 114. ISBN 978-1-118-01343-4.
  4. Tropea, Cameron; Yarin, Alexander L.; Foss, John F. (2007). Springer handbook of experimental fluid mechanics, Springer. pp. 661, 676. ISBN 978-3-540-25141-5.
  5. ISO 11040-4 –  Prefilled Syringes –  Glass barrels for injectables and sterilized subassembled syringes ready for filling
  6. ISO 11608-1: 2014 Needle-based injection systems for medical use —  Requirements and test methods–  Part 1: Needle-based injection systems
  7. ISO 11608-5:2012 Needle-Based Injection Systems for Medical Use-Requirements and Test Methods-Part 5: Automated Functions.
  8. ISO 14971: 2007; Medical Devices – Application of Risk Management to Medical Devices.
  9. Design Control Guidance for Medical Device Manufacturers, March 1997
  10. Applying Human Factors and Usability Engineering to Medical Devices. Guidance for Industry and Food and Drug Administration Staff, February 2016.

Design Formulation for Drug Delivery Devices

Design Formulation for Drug Delivery Devices
The design of delivery devices or syringes is based on fluid properties of the medicine or drug. It becomes more inconvenient or painful to the patient if the drug or fluid is with high viscosity or semi-solid type which needs high force to inject. So, it is very important to understand the pressure and force requirement for delivery of highly viscous fluid.

In pharmaceutical industries, medicines are developed to treat certain illnesses. There are several types of delivery systems with which these medicines can be administered into the human or animal body. Injectable medicines are mainly administered with the help of syringes or delivery devices. Syringes or delivery devices are used with needles to inject the medicine or drug into the body.

However, a major challenge is to develop the syringe or delivery device which can be used to deliver the drug under the skin with more comfort and less pain. Injecting the drug under the skin with the help of syringes is mostly dependent upon the fluid properties of the drug. The design of delivery devices or syringes is based on fluid properties of the medicine or drug. It becomes more inconvenient or painful to the patient if the drug or fluid is with high viscosity or semi-solid type which needs high force to inject.

So, it is very important to understand the pressure and force requirement for delivery of highly viscous fluid. Based on the force requirement to deliver the drug, the device designer can design and develop a delivery system which would be used by the patient or user with more comfort and less pain. For the measurement of force, injectable drugs or fluids are classified as Newtonian and non-Newtonian fluids. The information in this paper on a mathematical equation, experiments, and suggestions will help the pharmaceutical industries as a basis to design and develop the syringes or drug delivery devices to deliver highly viscous, semi-solid or visco-elastic type of drug or medicine. The design parameters or functional features of the drug delivery device can be collectively called as design formulation. So, for a drug-device combination product, both the things viz. design and drug formulations are equally important for its safety and efficacy.

Figure 1 shows a schematic diagram of the syringe system in which needle is pre-attached to the syringe barrel at frontend. This configuration is also called a syringe with a staked needle.

 

The syringe barrel or container is called a primary container as it holds the medicine and has direct contact with it. The needle has two open ends and one of it will remain inside the syringe barrel. The needle is made out of metal and comes in different gauges. The needle gauge is defined by its inner bore diameter, outer diameter, and wall thickness.

There are other syringe configurations in which needles can be attached at the front end of the syringe manually before the injection. The syringe barrel is filled with the drug fluid or medicine. The rubber stopper is placed inside the syringe barrel at the other end so that fluid will always remain inside the syringe barrel. The fluid will not come out of the needle unless there is an adequate amount of force is applied on the rubber stopper through the plunger rod to move it towards needle end. The plunger rod may be attached to the rubber stopper as shown. The material of construction (MOC) of the syringe barrel could be glass or plastic or metal. There are different types of plastics used for syringe barrel. In all cases, the inner surface of the syringe barrel should be smooth enough so that movement of rubber stopper becomes uniform and with minimum or negligible friction. The inner surface of the syringe barrel can be siliconized to make a smooth or frictionless movement of the rubber stopper inside it.

To administer the dose, the user has to insert the needle under the skin at the injection site of the body and then push the plunger rod forward to dispense the medicine. An adequate amount of force is required to push the plunger rod forward. It becomes uncomfortable and inconvenient to the patient or user if the force required to push the rubber stopper is more.

However, the needle insertion and drug delivery steps can be made automatic with the help of an auto injector delivery device. To design an auto-injector or prefilled syringe, the designer needs to understand the force or pressure required to dispense the medicine out of the needle.

To administer the medicine with comfort and less pain, it is very important to understand the design parameters or factors of a delivery device as well as fluid properties of drug which affect the force required to push the rubber stopper forward. The force required to inject medicine at a specific flow rate with a specific needle length and the gauge is called syringeability. The volumetric flow through the needle is governed by the Hagen-Poiseuille equation:

Above equation is used for Newtonian fluids. It shows that the major factors which affect the force required

to dispense the fluid or liquid medicine are as follows:

Medtech molder Aberdeen celebrates first quarter-century of success

Medtech molder Aberdeen celebrates first quarter-century of success

In 1994, Boyz II Men and Whitney Houston were in a virtual tie for the most popular song of the year, “I’ll Make Love to You” and "I Will Always Love You,” respectively; Forrest Gump was the top grossing film (and, in a strange echo with the present day, The Lion King was number two); the United States hosted the FIFA World Cup for the first time; and John H. Schmitz and his son, John M. Schmitz, founded Aberdeen Technologies, a supplier of molded plastic components. Aberdeen is celebrating a quarter century of success this year, and while it started out molding parts for a cross-section of sectors, including automotive and consumer goods, the founders’ expertise in medical molding predestined the company’s rapid success.

Aberdeen Technologies cleanroom
Aberdeen Technologies has approximately 400 feet of cleanroom space.

John H. Schmitz was Senior Vice President of a major medical device manufacturing company prior to co-founding Aberdeen, while his son John M. had been selling turnkey manufacturing systems to device manufacturers. They pooled their expertise in 1994 and began molding parts out of a rented space in a warehouse in Glendale Heights, IL. Only two years later, the business had grown to the point where they needed to relocate to a larger facility in Carol Stream, IL, where Aberdeen remains today. It currently has approximately 400 feet of cleanroom space and operates six presses—three of the 25-ton vertical insert molding machines are situated inside the cleanroom, which has space for a fourth press.

A medical molding first

You might say the technological foundations of Aberdeen were laid back in 1983. John M. Schmitz was working at Illinois Precision Corp., selling turnkey molding systems to medical device manufacturers, when an engineer from Baxter Edwards asked him about the feasibility of molding a multi-lumen heart catheter. “Up until that time, companies were mainly gluing tubing onto manifolds,” Schmitz told PlasticsToday. “However, he wanted to try over molding the individual extension lumens directly into a manifold. We built a prototype  mold, successfully molded clinical samples and went on to provide a full manufacturing cell for cleanroom production. A variation of this product still runs to this day,” said Schmitz.

Aberdeen Technologies multi-lumen catheter
Molded multi-lumen catheter.

The next milestone came a couple of years later, when the first Medical Design and Manufacturing (MD&M) trade show debuted in the ballroom of the Disneyland Hotel in Anaheim, CA. (Since then, MD&M has grown into the largest annual event of its kind in the Americas, filling the Anaheim Convention Center with a number of co-located shows, including PLASTEC West. It is organized by Informa Markets, which also produces PlasticsToday.) Schmitz brought a 25-ton vertical molding machine to the event, “the first piece of equipment to ever appear at the show.” There was some discussion initially about letting him run the machine on the show floor, but Schmitz ultimately got the green light and the “setup was a huge success, with dozens of medical device manufacturers interested in our insert molding technology. In addition to catheters, molded needles also became one of our specialties,” said Schmitz.

Consequently, when he and his father started Aberdeen in 1994, they already had a “wealth of knowledge to bring to the table, but also manufacturing experience that we helped pioneer and perfect that competitors are not necessarily able to provide,” said Schmitz.

Molding parts for medical device OEMs can't be an afterthought

Over the years, Aberdeen has adapted to a stream of regulatory and technological changes in the medical device industry, but Schmitz attributes its continued success to a commitment to certain core principles. First and foremost, he said, is a willingness to "go all in. Medical products cannot be an afterthought, something you just add to your product portfolio. You either live and breathe it, or you don’t,” said Schmitz.

One significant advantage Aberdeen has vis à vis competitors, added Schmitz, is the ability to design and build tooling in house. “Bill Walter, our Engineering Manager, and I have worked together for over 45 years. When we receive a drawing or file for a new medical device that needs quoting, sometimes we don’t even have to say a word to each other—just a look conveys that we know what will be required to perform to customer expectations. It is almost second nature, yet the joy and excitement of taking on a new project still remains,” Schmitz told PlasticsToday.

The “joy and excitement” show no signs of abating, as Aberdeen leans into its 26th year of operation. Moreover, with the recent addition of John David Schmitz to the team, “Aberdeen now has three generations working in the business.” As it celebrates its first quarter century, the company has renewed its vows to be a “one-stop shop for its customers providing solutions for device prototyping, mold designs, production runs and parts for first article approval.”

That Small Step Is Still There After 50 Years

 

Apollo 11 landing site captured from 24 km (15 miles) above the surface by NASA's Lunar Reconnaissance Orbiter(LRO). Tracks of the astronauts can be seen between the LM and various other discarded pieces of equipment. (Image source: NASA Goddard/Arizona State University)

The remnants of the footsteps are still there. Fifty years after Neil Armstrong and Buzz Aldrin walked on the surface of the moon, the evidence of humankind’s first venture off our small blue planet is still visible. The astronauts had spent over 21 hours on the lunar surface after their Lunar Module (LM) had landed there on July 20, 1969. They had explored for more than 2-1/2 hours the surface outside of their spacecraft. Then they blasted off using the ascent stage of the LM, and leaving behind the descent stage on the surface.

In November of 2009, NASA released images of the Apollo 11 lunar landing site in the Sea of Tranquility. The images, taken by the Lunar Reconnaissance Orbiter (LRO) from just 15 miles above the Moon’s surface, shows the discarded descent stage of the LM, as well as tracks created by the astronauts as they moved about in the dust on the surface.

One of the astronaut’s trails leads to the Passive Seismic Experiment Package (PSEP), which was set up to provide the first lunar seismic data. It continued to return data for three weeks after the astronauts left. Also visible in the LRO photo is the Laser Ranging RetroReflector (LRRR), which allows precise laser measurements between the Earth and Moon to be made. It is still operating to this day and the discarded cover of the LRRR can be spotted nearby, where it was dropped by one of the astronauts.

Another trail follows an unplanned excursion near the end of the time spent on the surface. Armstrong ran over to get a look inside Little West crater, about 50 meters (164 feet) from the LM. This was the farthest either astronaut ventured from the landing site. Armstrong and Aldrin's tracks during their time on the lunar surface cover less area than a city block.

An artist’s illustration of the LRO taking photographs and measurements of the surface of the Moon. ( Image source: NASA)

The LRO was launched on June 18, 2009 and entered lunar orbit on June 23, 2009. LRO’s mission is to help identify sites close to potential resources with high scientific value, favorable terrain, and the environment necessary for safe future robotic and human lunar missions. The LRO has also photographed all of the Apollo lunar landing sites, as well as the locations where various the jettisoned Lunar Modules have impacted the lunar surface, after having returned the astronauts safely to the orbiting Command Module.

According to NASA, the instruments on board the LRO spacecraft return a range of global data, including day-night temperature maps, a global geodetic grid, high resolution color imaging and the moon's UV albedo. There has been particular emphasis on the polar regions of the moon where continuous access to solar illumination may be possible, and the potential for frozen water in the permanently shadowed regions at the poles may exist. LRO data sets have been deposited in the Planetary Data System (PDS), a publicly accessible repository of planetary science information.

Because the Moon lacks any atmosphere that would cause erosion, short of a major meteor strike at the landing location, the only degradation of the tracks of footprints and equipment remaining on the moon comes from the impact of micro-meteors. It theory this means that the artifacts from the Apollo 11 Moon landing could remain undisturbed for centuries—or at least long enough to become a prime tourist attraction for the inhabitants for a future Moon base.

Senior Editor Kevin Clemens has been writing about energy, automotive, and transportation topics for more than 30 years. He has masters degrees in Materials Engineering and Environmental Education and a doctorate degree in Mechanical Engineering, specializing in aerodynamics. He has set several world land speed records on electric motorcycles that he built in his workshop.

            

Return to Earth and Splashdown

July 22-24

Apollo 11’s three parachutes bring it safely home to a splashdown in the Pacific Ocean. (Image source: NASA)

Returning from the Moon took two days for Apollo 11, during which time two more television transmissions were made by the astronauts.

Re-entry procedures were initiated on July 24, 44 hours after leaving lunar orbit. The Command Module (CM) separated from the Service Module (SM) and was rotated around to a heat-shield-forward position. Because of bad weather in the original Pacific Ocean target area, the landing point was changed by about 250 miles. The CM Columbia entered the Earth’s atmosphere at 12:35 pm, protected from the intense heat, caused by friction with the air, by the spacecraft’s heat shield.

President Richard Nixon welcomes home the Apollo 11 astronauts (from left, Neil Armstrong, Michael Collins, and Buzz Aldrin.) The astronauts were quarantined after their mission to ensure they did not bring back any contamination from the moon. (Image source: NASA)

As Apollo 11 entered the denser part of the atmosphere, three parachutes were deployed and Columbia splashed down 13 miles away from the USS Hornet recovery ship. Apollo 11’s total flight time to the Moon and back had been 195 hours, 18 minutes, and 35 seconds. After the spacecraft hatch was opened by the recovery crew, the astronauts donned isolation suits to ensure that they wouldn’t spread any possible lunar microbes. President Richard Nixon was on-board the Hornet to congratulate and welcome the astronauts home. These three men had just returned from one of humankind’s most remarkable, challenging, and historic journeys.

 

Leaving the Lunar Surface

July 21, 1969

The ascent stage of the Lunar Module Eagle returns from the lunar surface and approaches the Command Module Columbia for its rendezvous. (Image source: NASA)

After a seven hour rest period that included some fitful sleep, Armstrong and Aldrin prepared Eagle to leave the lunar surface. The Lunar Module (LM) was designed in two parts—the descent stage had done its part in bringing the pair of astronauts to a touchdown on the surface. Now, the ascent stage, with its crew quarters and separate rocket engine would separate from the descent stage and return the men to lunar orbit.

Grumman, who had designed and built the LM knew that the single rocket engine in the ascent stage was the only chance that the astronauts would have to leave the lunar surface. The company had simplified its design to make it as bullet-proof as possible. They had also included a variety of redundant systems to help ignite the engine, should anything go wrong with the primary system.

After 21 hours, 36 minutes on the moon's surface, the ascent stage engine fired perfectly and Eagle began its return to lunar orbit. The engine was shut down 435 seconds later when the Eagle reached an initial orbit of 11 by 55 miles above the moon, and when Columbia was on its 25th revolution. A short time later Eagle’s reaction control system, or RCS, fired to place Eagle into a circular orbit at about 56 miles, some 13 miles below and slightly behind Columbia.

Attached to the leg of the Lunar Module Descent stage was a plaque that contained the signatures of the three Apollo 11 astronauts, and President Richard Nixon. (Image source: NASA)

In addition to their footprints, Armstrong and Aldrin had left on the lunar surface commemorative medallions bearing the names of the three Apollo 1 astronauts who lost their lives in the launch pad fire, and two cosmonauts who had died in accidents. A one-and-a-half inch silicon disk, containing micro miniaturized goodwill messages from 73 countries, and the names of congressional and NASA leaders, also was left behind. On the leg of the Eagle descent stage that remained behind was a plaque that read, "Here men from the planet Earth first set foot upon the Moon July 1969, A.D. We came in peace for all mankind."

Eagle docked with Columbia on its 27th orbit of the moon. Docking with Columbia occurred on the CSM's 27th revolution. Armstrong and Aldrin moved more than 48 pounds of the all-important moon rocks they had collected from the surface into the Command Module and four hours later, the crew jettisoned the faithful LM.

Returning to the Earth was initiated with a Trans-Earth injection as the Service Module engine fired for two-and-a-half minutes when Columbia was behind the moon. It had been a busy and stressful two days and as Columbia began its long journey home, the three astronauts slept for about 10 hours.

 

“We came in peace for all mankind."          

 

New Technology Could Dramatically Increase Solar Output

Researchers around the world have been working for years to improve the energy efficiency of silicon-based solar cells to help promote alternative energy production.

One problem that has stumped researchers is that in these cells, there is an absolute limit on overall efficiency based on how they function--each photon of light can only knock loose a single electron, even if that photon carried twice the energy needed to do so.

Now researchers at MIT may have solved this dilemma with a method that allows high-energy photons striking silicon to knock loose two electrons instead of one. The team—comprised of researchers at both MIT and Princeton—paves the way for a new kind of solar cell with unprecedented efficiency, they said.

The research team included MIT graduate student Markus Einzinger, professor of chemistry Moungi Bawendi, and professor of electrical engineering and computer science Marc Baldo. While the technology the team invented is new, the concept they used to create it has been known for decades.

That concept is called “singlet exciton fission,” which is the process by which light’s energy splits into two separate packets of energy that move independently. The research team first demonstrated this process could work for solar-energy production six years ago; now they are completing years of work with its integration into a fully functioning solar cell, Baldo said.

Diagram depicts the process of “singlet fission,” which is the first step toward producing two electrons from a single incoming photon of light. MIT applied this principle to solar cells, which could improve their energy production and efficiency. (Image source: MIT researchers)

Pushing the Efficiency Envelope

Conventional silicon cells theoretically have a maximum efficiency of about 29.1 percent conversion of solar energy; current solar cells sold on the market are typically around 20 percent efficiently, give or take. However, with the new approach could add several percentage points to that maximum output, researchers said.

To demonstrate that the principle worked, researchers used an organic photovoltaic cell, which is less efficient than a silicon cell. In the current case, they needed to transfer two electrons from top collecting layer made of tetracene into the silicon cell, which proved difficult, Baldo said in a press statement.

The key materials to splitting the energy of one photon into two electrons are called excitons, or “packets of energy [that] propagate around like the electrons in a circuit,” but with far different properties than electrons, Baldo said in the statement.

“You can use them to change energy--you can cut them in half, you can combine them,” he said.

In singlet exciton fission, the exciton first absorbs a photon, forming an exciton that rapidly undergoes fission into two excited states, each with half the energy of the original state, Baldo said in the statement.

Researchers than had to couple that energy over into a non-excitonic material--the silicon of the cell. This is something no researcher had done before, according to the team.

Middle Ground

To achieve their goal, researchers first coupled the energy from the excitonic layer into an excitonic, inorganic material called quantum dots.

“That worked; it worked like a charm,” Baldo said in the statement.

Ultimately, this intermediate step was integral to demonstrating singlet exciton fission works in a silicon solar cell, Troy Van Voorhis, a professor of chemistry at MIT who worked on the original research, said in a press statement.

“It turns out this tiny, tiny strip of material at the interface between these two systems [the silicon solar cell and the tetracene layer with its excitonic properties] ended up defining everything,” he said. “It’s why other researchers couldn’t get this process to work, and why we finally did.”

The team published a paper on its work in the journal Nature.

Researchers said they still have a long way to go to actually use what they’ve demonstrated to improve the efficiency of solar cells on the market—which still aren’t at their maximum efficiency potential.

“We still need to optimize the silicon cells for this process,” Baldo said in a press statement

Researchers plan to continue their work to stabilize the materials they’re working with for durability, as well as adding another kind of cell—perhaps one of perovskite material—over the silicon, he added.

Elizabeth Montalbano is a freelance writer who has written about technology and culture for more than 20 years. She has lived and worked as a professional journalist in Phoenix, San Francisco and New York City. In her free time she enjoys surfing, traveling, music, yoga and cooking. She currently resides in a village on the southwest coast of Portugal.

 

Drive World with ESC Launches in Silicon Valley

This summer (August 27-29), Drive World Conference & Expo launches in Silicon Valley with North America's largest embedded systems event, Embedded Systems Conference (ESC). The inaugural three-day showcase brings together the brightest minds across the automotive electronics and embedded systems industries who are looking to shape the technology of tomorrow.
Will you be there to help engineer this shift? Register today!