(November 17, 2015) Flexible
sensors have been developed for use in consumer electronics, robotics, health
care, and space flight. Future possible applications could include the creation
of ‘electronic skin’ and prosthetic limbs that allow wearers to ‘feel’ changes
in their environments.
One problem with current flexible sensors, however, is that
they can be easily scratched and otherwise damaged, potentially destroying
their functionality. Researchers in the Department of Chemical Engineering at
the Technion – Israel Institute of Technology in Haifa (Israel), who were
inspired by the healing properties in human skin, have developed materials that
can be integrated into flexible devices to “heal” incidental scratches or
damaging cuts that might compromise device functionality. The advancement,
using a new kind of synthetic polymer (a polymer is a large molecule composed
of many repeated smaller molecules) has self-healing properties that mimic
human skin, which means that e-skin “wounds” can quickly “heal” themselves in
remarkably short time – less than a day.
“The vulnerability of flexible sensors used in real-world
applications calls for the development of self-healing properties similar to
how human skins heals,” said self-healing sensor co-developer Professor Hossam
Haick. “Accordingly, we have developed a complete, self-healing device in the
form of a bendable and stretchable chemiresistor where every part – no matter
where the device is cut or scratched – is self-healing.”
The new sensor is comprised of a self-healing substrate,
high conductivity electrodes, and molecularly modified gold nanoparticles. “The
gold particles on top of the substrate and between the self-healing electrodes
are able to “heal” cracks that could completely disconnect electrical
connectivity,” said Prof. Haick.