A self-powered sensor developed at the University of Waterloo in Canada could allow doctors to remotely monitor the recovery of surgical patients.
The small, tube-like device, pictured, is designed to be fitted to braces after joint surgery 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,” said Hassan Askari, an engineering doctoral candidate at Waterloo.
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,” said Askari. “It is its own power source.”
That makes the device well-suited for applications that put a premium on reliability and where it would be difficult or expensive to replace worn-out batteries.
Askari estimated the sensors – about six centimetres long and one centimetre wide – could be commercially manufactured for $5 to $10 each.
Research is now focused on making them smaller and more sensitive using triboelectricity alone.
A study detailing their work appears in the journal Sensors and Actuators A: Physical.
Source: University of Waterloo, Canada
