Eggshell membrane used to generate electricity

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.

“However, bio-based green energy is still effectively not explored to fulfil the energy demand of contemporary human mankind,” said Bhanu Bhusan Khatua, a professor at IIT Kharagpur in West Bengal. “Reported biopiezoelectric 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.

The device may be able to replace conventional ways of powering medical devices in the future, researchers said.

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.