IIT-Guwahati researchers develop cost-effective motion sensor for healthcare application

New Delhi: Researchers from the Indian Institute of Technology, Guwahati, have developed a cost-effective, gel-based wearable device that is capable of recording motion signals that can have healthcare applications.

According to officials, the organohydrogel sensor is placed on patients in a comatose state or facing a similar condition through a wireless device and a smartphone can monitor subtle movements over an extended period.

This provides healthcare professionals with invaluable insights into a patient's condition and appropriate interventions can be taken.

Flexible and wearable electronics play a pivotal role in augmenting human capabilities, serving functions like artificial skin and prosthetics to assist human movements or integrating with clothing and the body in areas like bioelectronics, wearable sensors, energy-storage devices and stretchable optoelectronic devices, said Debapratim Das of the chemistry department at IIT-Guwahati.

"Stretchable wearable devices are extremely beneficial for sensing minor movements of body parts. In situations where monitoring minute limb movements is crucial, such as in comatose patients or similar conditions, stretchable gels are used.

"However, the current gel technologies exhibit limitations in mechanical properties, lacking ultra-stretchability and self-healing abilities. Additionally, they often lose sensitivity in extreme temperature conditions," he added.

Addressing this gap, the research group at IIT-Guwahati has fabricated an organohydrogel.

Das explained that the innovative material exhibits remarkable characteristics, including exceptional stretchability (1000 pc at strain, sustained for over 100 cycles), self-healing capabilities, anti-freezing, conductivity, as well as outstanding mechanical strength and adhesive properties even after it is kept at minus 20 degrees Celsius for a long time.

"We introduced a secondary cross-linking to significantly boost the mechanical properties of the gel and employed precise ratios of glycerol and water to ensure environmental tolerance from minus 20 to 40 degrees Celsius. Furthermore, our findings reveal the gel's remarkable biocompatibility, allowing its safe application on human skin without any side effects," he said.

The findings of the study have been published in the prestigious ACS Applied Material and Interfaces journal. The co-authors include Ritvika Kushwaha, Mouradeep Dey, Kanika Gupta and Biman B Mandal.

"During our practical wearable sensing tests, the sensor showed high sensitivity to detect major human joint motions such as elbow, finger and wrist bending as well as micro-motions such as muscle movement around the throat during swallowing and expressions such as smiling and frowning.

"Because of its wide environment tolerance, it can also be used under extreme conditions like sub-zero temperature during mountaineering," said Biman B Mandal of the Department of Biosciences and Bioengineering at IIT-Guwahati, Furthermore, the researchers fabricated a device that was connected through a smartphone via Bluetooth where signals were recorded upon deformation of the smart gel, which shows that the gel holds great promise as a wearable device.