IIT scientists use eggshell membrane to generate electricity

​New Delhi: Scientists from Indian Institute of Technology (IIT) Kharagpur have used eggshell proteins to develop tiny devices that can harvest electricity from body movements, and could power wearable sensors and devices in future. Proteins found in eggshell membranes have piezoelectric properties, that is, under mechanical stress they produce electricity, researchers said. 

Bio-inspired piezoelectric materials are considered to be an excellent energy harvesting source, since they are non-toxic and bio-compatible. They also have the ability to generate significant power to the energy deficient world without contributing to environmental pollution. 

"Reported bio-piezoelectric have serious drawbacks, such as availability, toxicity, non-biodegradable, non-biocompatibility, industrially unfavorable as well as complex fabrication steps, which limit its potential applications in real life," said Khatua, who led research published in the journal Materials Today Energy. 

To build the device, researchers including those from Pohang University of Science and Technology in South Korea, isolated the soft membrane present inside the eggshell. The membrane was coated on both sides with thin copper tapes, and gold electrodes were attached to them. The arrangement was encapsulated in silicon-based organic polymer. Researchers showed that assembling five of these devices provides enough voltage to light-up over 90 green LEDs. The findings suggest that the advance can be effectively commercialised. 

The device is ultrasensitive towards very minute pressure arising from pulse, body motions at rest and walking conditions and water drop, suggesting that it could be used to power numerous applications including fitness trackers, health monitors and sensors. The work would have a significant role towards up-lifting the green energy harvesting technology as self-powered implantable and wearable electronics, researchers said.