Thin-Film Batteries Boost Design Options

Solid-state thin-film batteries with thicknesses of just 15 µm can be fabricated in most shapes and sizes to fill a variety of requirements. Developed by Oak Ridge National Laboratory (Oak Ridge, TN; www.ornl.gov), the rechargeable power cells are available with lithium or lithium-ion chemistries. The components are sputtered or evaporated onto a selection of solid substrates, including silicon, alumina, glass, and plastics. "Because the batteries are rechargeable, they only have to be large enough to supply the power required for a single duty cycle," says researcher Nancy Dudney. "So far, we have constructed batteries with areas of 0.5–25 cm², but there aren't any fundamental lateral size restrictions, either larger or smaller." The products can be formed in almost any shape, as long as the design allows the anode and cathode to be separated by a thin layer of electrolyte.

Despite their small size, these batteries have many features. With high energy per unit of volume and mass, they can be cycled many times. The stable units also do not experience a measurable change after years of storage. A wide operating temperature range allows cycling in temperatures of –25° to 100°C. Implantable medical devices, hearing aids, remote sensors, miniature transmitters, and smart cards are among the potential applications. The batteries have also been used in transdermal electrodes to eliminate interference and improve the reliability of ECG and electroencephalography systems.

Vesta Increases Molding Capabilities

Vesta Inc. (Franklin, WI; www.vestaweb.com), a manufacturer of custom silicone components and assemblies, has acquired K-Sil Inc. (Portage, WI), a high-volume supplier of medical-grade silicone. The acquisition expands Vesta's high-volume liquid injection molding capabilities.

The acquisition offers Vesta greater automation with better material utilization, according to company president Glenn Hubbard. "K-Sil's cold runner tooling technology is more conducive for high-volume production and will allow us to compete on a price basis," says Hubbard.

The newly acquired facility, now named the Portage Div., has a Class 100,000 cleanroom and is FDA and NSF registered.

Many suppliers to device OEMs traditionally unveil their newest products and services at the Medical Design & Manufacturing shows, and this year's MD&M East was no exception. Three products that caught our eye are described below: a polyolefin with the tactile qualities of PVC, a guidewire grinder that takes flexibility and accuracy to new heights, and CAD/CAM software that will straighten out any problem curves lurking in your design.

Zachary Turke