World's Smallest Radiometer Could Power Medical Devices

Although the name may not be familiar, the design of the radiometer--a light-powered, propeller-style, rotating vane ensconced in a bulb--is a common product that most everyone has encountered in a toy or novelty shop. Researchers from the University of Texas at Austin, however, are working on turning a novelty into a novel concept for potentially powering future medical devices.

Claiming to have developed the world's smallest radiometer, the researchers have modified and miniaturized the standard design in order to make it suitable for in vivo use. In contrast to traditional radiometers, the group's version features curved, rather than flat, vanes that are coated with gold nanoparticles to enhance light absorption. However, the team's radiometer still operates on the same principles: A temperature difference created by the contrasting two sides of the vanes creates a significant temperature difference, which, in turn, generates movement.

"When there is a temperature difference between the gas and the room, there's a flow of air," Li-Hsin Han of the University of Texas at Austin told Inside Science. "We needed a tiny little motor to place at the end of a catheter, and we realized we could build a micromotor much smaller for cheaper--and with less effort--using this method."

Driving the radiometer-related research, as Han notes, was the quest for a micromotor to assist with efforts in optical coherence tomography. Han hopes that the micromotor could some day help capture 3-D images from inside tiny blood vessels and arteries, and aid in cancer imaging.

Read more about this nascent technology at Inside Science.