The humble silkworm, known best for its contribution to the textile industry, will now find use in an uncommon territory — in augmenting computer memory1.

The research team: (L to R) Mrinal Hota, Banani Kundu, Chinmay Maiti and Subhas Kundu.

A research team from Kharagpur-based Indian Institute of Technology (IIT) has developed a new bio-memristor device using fibroin, a silk protein isolated from the cocoons of Bombyx mori silkworm . Memristor devices are electronic circuits which remember changes in the current passing through them by changing their resistance.

The researchers have used silk fibroin protein as a biomaterial for such devices. They say the silk protein could find application in advanced bio-inspired, large scale integration circuit designs as well as in biologically inspired synapse links for energy-efficient computing that mimic information processing in nerve cells.

Subhas Kundu, one of the researchers, says they could also be used for hybrid metal oxide semiconductor devices.

Electronic devices derived from biomolecules are inexpensive and lightweight. However, their use is restricted because of compatibility issues with circuit materials. Among biomolecules, silk protein is bio-compatible and biodegradable and has shown potential in tissue engineering and regenerative medicine but its virtues in designing electronic devices such as memristors had not yet been explored.

The IIT researchers set out to do that. They made a solution of the protein from cocoons of B. mori silkworm. The fibroin solution was smeared on an indium tin oxide-coated optically transparent glass substrate. Electrochemical experiments and scanning tunneling microscopy were then carried out. The researchers found that the silk fibroin film showed 'switching' properties due to formation and rupture of conducting filaments.

"Interestingly, the switching cycle resembles a typical nonvolatile memristor composed of ON and OFF states," says Subal Kar from the Institute of Radio Physics and Electronics of Calcutta University. However, the stability and durability of this bio-memristor device needs to be tested to compete with existing electronic memristors, he says.

The authors of this work are from: Department of Electronics and Electrical Communication Engineering Department of Biotechnology Indian Institute of Technology, Kharagpur, India.