Cunjiang Yu, an associate professor of mechanical engineering at the University of Houston, said the rubbery semiconductor material, which has high carrier mobility, can be easily scaled for manufacturing, based upon assembly at the interface of air and water.
According to a study on the material, this interfacial assembly and the rubbery electronic devices suggest a pathway toward soft, stretchy rubbery electronics and integrated systems that mimic the mechanical softness of biological tissues, suitable for a variety of emerging applications, said Yu.
The smart skin and medical robotic hand are just two potential applications created by the researchers to illustrate the utility of the invention.
Traditional semiconductors are brittle, and using them in otherwise stretchable electronics has required special mechanical accommodations. Previous stretchable semiconductors have had drawbacks of their own, including low carrier mobility – the speed at which charge carriers can move through a material – and complicated fabrication requirements.
To overcome this, Yu and collaborators last year reported that adding minute amounts of metallic carbon nanotubes to the rubbery semiconductor of P3HT, a polydimethylsiloxane composite, improves carrier mobility, which governs the performances of semiconductor transistors.
According to Yu, this new scalable manufacturing method for these high performance stretchable semiconducting nanofilms, along with the development of fully rubbery transistors, represent a significant step forward.
The production is simple, he said. A commercially available semiconductor material is dissolved in a solution and dropped on water, where it spreads; the chemical solvent evaporates from the solution, resulting in improved semiconductor properties.
Yu added that this is a new way to create high-quality composite films, allowing for consistent production of fully rubbery semiconductors.
Electrical performance is retained even when the semiconductor is stretched by 50 per cent, the researchers reported, adding that the ability to stretch the rubbery electronics by 50 per cent without degrading the performance is a notable advance. They stressed that human skin can be stretched only about 30 per cent without tearing.