Researchers with Lawrence Berkeley National Laboratory and the University of California, Berkeley, say that they have created tactile sensors from composite films of carbon nanotubes and silver nanoparticles similar to the highly sensitive whiskers of cats and rats. These new e-whiskers respond to pressure as slight as a single Pascal, about the pressure exerted on a table surface by a dollar bill. Among their many potential applications is giving robots new abilities to “see” and “feel” their surrounding environment.
Their electronic whiskers consist of high-aspect-ratio elastic fibers coated with conductive composite films of nanotubes and nanoparticles. In tests, the whiskers were 10 times more sensitive to pressure than all previously reported capacitive or resistive pressure sensors, they reported.
To create the whiskers, they used a carbon nanotube paste to form an electrically conductive network matrix with excellent bendability. To this carbon nanotube matrix they loaded a thin film of silver nanoparticles that endowed the matrix with high sensitivity to mechanical strain. The composite can then be painted or printed onto high-aspect-ratio elastic fibers to form e-whiskers that can be integrated with different user-interactive systems.
As proof-of-concept, the researchers successfully used their e-whiskers to demonstrate highly accurate 2D and 3D mapping of wind flow. But, they say that in the future, e-whiskers could lead to wearable sensors for measuring heartbeat and pulse rate, and should have a wide range of applications for advanced robotics, human-machine user interfaces, and biological applications.