Stepping up and harvesting energy

Every footstep you take produces a minuscule quantity of energy. But can this energy, usually wasted, be harvested to power medical implants or even mobile phones?

A team of biomedical engineers at the Indian Institute of Technology (IIT) Delhi has made some progress on this. The researchers led by Arnab Chanda of the Department of Biomedical Engineering at IIT Delhi have designed an insole studded with a series of piezoelectric transducers, which convert kinetic energy from footsteps into electrical energy. A transducer is a device that converts variations in a physical quantity such as pressure and temperature into an electrical signal, or vice versa.

The scientists were able to capture energy from footsteps using a six-layered compartmental insole that they fabricated using additive manufacturing techniques. They tested its capability to charge a battery using different activities such as running and walking. The scientists reported their work in the journal e-Prime on January 18.

"This is a work in progress. This is a footwear-based power harvesting system where a set of piezo-based optimised circuits and sensors could harness a certain amount of power to charge certain ear-based wearables and smartwatches," says Chanda, who holds an additional faculty position at the All India Institute of Medical Sciences, New Delhi.