Engineers at the University of Waterloo have developed a self-powered sensor designed to be fitted to braces after joint surgery that they suggest could allow physicians to remotely monitor their patients’ recovery.

The sensor, described as a small, tube-like device, can be programmed to wirelessly send information to computers, smartphones, or smartwatches to track range of motion and other indicators of improvement.

“That data would be continuously collected, so it would be as though the physician or physiotherapist was always there, always observing the patient,” says Hassan Askari, an engineering doctoral candidate at University of Waterloo, in a media release.

Development of the device is described in a study published in Sensors and Actuators A: Physical.

A prototype built and tested by the researchers combines electromagnetism and triboelectricity, a relatively new energy harvesting technique that involves bringing different materials together to produce current.

When bent or twisted, the device generates enough electricity for sensing and powering electronic circuits for processing and wireless signal transmission.

“The aim was to develop a sensor that works without having a battery attached to it,” says Askari, in the release. “It is its own power source.”

The same sensor could also be used in a variety of other ways, including in the tires of autonomous vehicles to detect and respond to icy roads, it is suggested in the release.

Research is now focused on making them smaller and more sensitive using triboelectricity alone. Software is also being developed to process signals for the tire application.

When attached to the inside of tires, they could sense changing road conditions and instantly send information to control systems to enable self-driving vehicles to make adjustments, the release explains.

“Based on the forces, the interaction between the road and the tires, we could actually detect ice or rain,” Askari states. “That is extremely important information for autonomous driving.”

[Source(s): University of Waterloo, EurekAlert]