KOLKATA: A novel research by scientists at IIT-Kharagpur has shown the way to generate electricity from onion peel. Eateries saddled with bags of the waste product can now turn them into a power source - the skin of a single onion can light up 12 green LEDs.Professor Bhanu Bhusan Khatua , his PhD scholar Sumanta Kuman Karan and their team at the Material Science Centre (MSC) have developed the green technology after a year-long research. The result has been tested and improved by scientists, led by Jin Kon Kim , at Pohang University of Science and Technology Postech ), South Korea . The paper was published in the Nano Energy journal in October.The researchers have applied for a patent on the technology which can be used in places where onions are used in bulk. "The technology can be easily adopted at restaurants where a lot of onion peels are accumulated on a daily basis. Only, they end up in bins," said Khatua.His research found that only half-an-inch of an onion peel is enough to generate 20 volts. "If you gather the peels of six onions and place them in a series, they can light-up 80 LEDs or charge your laptop or mobile phone," the scientist said.To make the system work, the user has to encapsulate the onion skin and fabricate the device - the size of an adhesive plaster. The device, called nanogenerator, must then be attached to mechanical or bio-mechanical energy sources to generate electricity.Nanogenerators convert kinetic energy created from vibrational and mechanical sources into electrical power, doing away with the need for external circuits or batteries. In scientific jargon, the devices are called bio-piezoelectric nanogenerators (BPNG). "The fabricated nanogenerator will be capable of harvesting many kinds of mechanical energies, including body movements, wind flow and machine vibrations," said Khatua."This is the first time that a nanogenerator has been designed using onion peel as the medium for generating electricity. Onion peels are bio-degradable and bio-waste material. Unlike other piezoelectric materials, they don't require pre-treatment or electrical polling. We just have to place the onion peel-based nanogenerator, connected with the smart electronic devices, under the mechanical or bio-mechanical energy sources," said Khatua.The electricity in the cellulose-based onion skin is produced as a result of structural changes in the cellulose under external mechanical stress or force, including movements as delicate as the touch of a finger or a heart pulse."We are currently developing the technology for industrial and domestic application, and applying for its patent," Khatua added."The onion skin used to fabricate the nanogenerators will keep on generating electricity until they are naturally destroyed,"he said. Since harvesting energy through human body movement (joint movement) is an emerging trend for smart applications, IIT-Kharagpur's effort to commercialize electricity generated from onion peel may go a long way in providing free power to rural India."We look forward to the day onion skin-based bio-piezoelectric nanogenerators find applications in health care as a self-powered energy source for pacemakers or as a sensor for monitoring heart pulse," Khatua said.