KOLKATA: Indian scientists have discovered a UV-sensitive substance on silk cocoon membranes which converts light into electricity, a finding they say has opened up possibility of designing a bio-solar battery for medicine and also has potential applications in development of third generation solar cells.

Researchers at IIT-Kanpur, Delhi Technological University, Defense Institute of Physiology and Allied Sciences, Solid State Physics Laboratory (Defense Research and Development Organisation) have shown how a pupa in a silk cocoon senses light.

"A pupa which is growing inside cocoon has a brain circuit which is regulating its growth to an adult moth. This circuit and transformation is influenced by environmental factors like light, humidity and temperature.

"We have discovered a simple flavonoid molecule on the surface of the cocoon that acts as a UV absorber," Mainak Das, Associate Professor, Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, told IANS.

Flavonoids are found in most fruits and vegetables and the researchers demonstrated the role of the particular flavonoid (called quercetin) by connecting the cocoon (wild silkworm species of Antheraea mylitta, commonly called Tasar silk) with an electrode and shining light on it.

"When you use regular light, there was a slight shift in current and voltage and when you shine UV light there is a many-fold increase in current and voltage," explained Das.

Published on February 24 in Nature Scientific Reports, the findings has implications for development of third-generation dye-sensitive solar cells.

The study is a continuation of an earlier work in which the team found that silk cocoon membrane has an inherent ability to sense the change in temperature and humidity of the surrounding environmentAand convert it into electricity.

Read Also: Watch out for the Best Offline Music Apps in 2016

Pro-Apple Protest Against FBI In New York