Researchers at IIT Kharagpur have discovered a way of lighting LED bulbs using spider silk as the source of electricity.
It may sound incredible, but it is a process known in science as ‘piezo-electric effect’, which refers to the property of certain (piezo-electric) materials, which produce electricity when subjected to stress. Conversely, if electricity is applied, they stress themselves. Piezo-electric material derived from living organisms are called bio-piezo-electric materials.
Now, it transpires that natural spider silk is a good bio-piezo electric material.
Spider silk fibers having remarkable protein sequence structure contain nature’s most outstanding mechanical properties and unrivalled elasticity along with biocompatibility and biodegradability. Unfortunately, it remains completely unidentified how the mechanical properties of spider silk effectively contribute to the performance and integrity on piezoelectric nanogenerator.
Using piezoresponse force microscopy (PFM), IIT Kharagpur researchers led by Bhanu Bhushan Khatua, Sumanta Kumar Karan, Sandip Maiti, Sarbaranjan Paria, Anirban Maitra and Suman Kumar Si, helped by two South Korean scientists, have designed a mechanically robust ‘spider silk bio piezoelectric nanogenerator (SSBPNG)’ using nature driven spider silk that exhibits high energy conversion efficiency (≈ 66%), high output voltage (≈ 21.3 V) and current (≈ 0.68 μA) with instantaneous power density of ≈ 4.56 μW/cm2. The fabricated device is biocompatible and ultra-sensitive towards physiological signal monitoring such as arterial pulse response which can be useful for potential biomedical applications.
“Although spider silk fibers show nature’s most outstanding mechanical properties, for example, excellent tensile strength and elasticity, and remarkable protein sequence structure, it remains completely unidentified how the mechanical properties of spider silk fibers effectively contribute to the performance of a piezoelectric nanogenerator (PNG),” Khatua has told Nanowerk magazine.
The technology, of course, is to be perfected. But it opens up a new vista for research. Spider silk has long been known to be a material of several desirable mechanical properties. Add a layer of energy to them, they could become an industrial material with a big market. So watch this space.