A group of scientists from Stanford University has created an artificial “skin” that acts as a stretchable, super-thin pressure sensor.
The Bao Research Group led by Zhenan Bao has demonstrated the film, which is made from single-wall carbon nanotubes bent to act as springs. The real breakthrough, however, isn’t just creating a stretchable film that returns to its original shape: it’s being able to finely measure the force applied either through stretching or compression.
The film is created by spraying the carbon nanotubes in liquid suspension onto a thin layer of silicon. The silicon is then stretched, which aligns some of the nano-bundles; when released, some of the tubes are bent into a spring-like configuration. Applying this stretching in two axes creates a film that the researchers say can be “stretched in any direction” while completely rebounding afterwards.
This is turned into a sensor by coating both sides of a silicon substrate with the nanotube film. The silicon stores charge, and its capacity is proportional to its thickness.
"This sensor can register pressure ranging from a firm pinch between your thumb and forefinger to twice the pressure exerted by an elephant standing on one foot," said team member Darren Lipomi, a postdoctoral researcher in Bao's lab.
The lab nominates prosthetics and robotics as possible applications for the sensitive film. Its work has been published online in Nature Nanotechnology.
Bao was one of the co-authors of the paper that led to the so-called “Schön scandal”, in which lead author Jan Schön claimed to have created molecular-scale transistors. Schön was accused of scientific fraud and later had his PhD revoked; however, Wikipedia says all of his co-authors were cleared of misconduct by a report commissioned by Bell Laboratories in 2002.
Here's Stanford's video demonstration of the film. Enjoy. ®