Researchers have made a groundbreaking discovery by creating a uniform 2D layer of silk protein on graphene. This innovation holds immense promise for developing biodegradable electronic devices and advanced health sensors.
Silk, known for its ancient luxury and durability, is now set to revolutionize the future of microelectronics. Researchers led by the Department of Energy’s Pacific Northwest National Laboratory (PNNL) have achieved a remarkable scientific feat. They have successfully created a uniform two-dimensional (2D) layer of silk protein fragments, known as fibroins, on graphene — a carbon-based material celebrated for its excellent electrical conductivity.
“These results provide a reproducible method for silk protein self-assembly that is essential for designing and fabricating silk-based electronics,” lead author Chenyang Shi, a postdoctoral research associate at PNNL, said in a news release. “It’s important to note that this system is nontoxic and water-based, which is crucial for biocompatibility.”
The combination of silk and graphene could form highly sensitive, tunable transistors. These advanced materials are poised to greatly benefit the microelectronics industry, particularly for wearable and implantable health sensors.
The team also envisions their potential as critical components in memory transistors, or “memristors,” which are integral to neural computing networks. These memristors would enable computers to mimic the human brain’s functionality, representing a significant leap in computational technology.
A Rich History, A Bright Future
Silk’s journey from a coveted commodity traded along the ancient Silk Road to a symbol of luxury in European markets is well-documented. Its inherent properties — elasticity, durability and strength — have led to its adoption in various advanced material applications.
“There’s been a lot of research using silk as a way of modulating electronic signals, but because silk proteins are naturally disordered, there’s only so much control that’s been possible,” James De Yoreo, a Battelle Fellow at PNNL and a professor of materials science and engineering at the University of Washington, said in the news release. “So, with our experience in controlling material growth on surfaces, we thought ‘what if we can make a better interface?’”
By meticulously controlling the reaction conditions, the team was able to add individual silk fibers to a water-based system in a precise manner. Their efforts resulted in a highly organized 2D layer of protein packed in parallel β-sheets, providing the structural stability required for biological electronics. This new form of silk is ultrathin — less than half the thickness of a strand of DNA — marking it suitable for the miniaturization essential in bio-electronics.
The practical implications are vast.
“This type of material lends itself to what we call field effects,” added De Yoreo. “This means that it’s a transistor switch that flips on or off in response to a signal. If you add, say, an antibody to it, then when a target protein binds, you cause a transistor to switch states.”
Future Horizons
The study, published in Science Advances, is a pioneering step towards controlled silk layering for functional electronics. Future research will focus on enhancing the stability and conductivity of silk-integrated circuits. The team is also exploring the potential for biodegradable electronics, which could revolutionize green chemistry in electronic device manufacturing.
The interdisciplinary study was co-led by PNNL materials scientist Shuai Zhang and Xiang Yang Liu of Xiamen University, with significant contributions from researchers at the University of Washington, Lawrence Berkeley National Laboratory and North Carolina State University.
As silk evolves from a fabric of the past to a material of the future, its role in creating eco-friendly, cutting-edge electronic devices could be profound, firmly intertwining the threads of history with the fabric of tomorrow’s technology.