University of Nebraska at Lincoln researchers Ravi F. Saraf and Vivek Maheshwari have developed a high resolution touch sensor based on a thin-film of semiconductive material sandwiched betweent two electode layers. This gives the device the ability to discern the finer features of text on a penny (as shown above).
“If you look at the current status of these tactile sensors, the frustration has been that the resolution of all these devices is in the range of millimetres,” explained Professor Ravi Saraf, an engineer from the University of Nebraska in Lincoln, US, and a co-author of the paper.
“Whereas the resolution of a human fingertip is about 40 microns, about half the diameter of a human hair, and this has affected the performance of these devices.”
But Professor Saraf and colleague Dr Vivek Maheshwari, also from the University of Nebraska, were able to attain this high level of sensitivity by creating a very thin film made up of layers of metal and semiconducting nanoparticles flanked at the top and bottom by electrodes.
When the film touches a surface any pressure or stress squeezes the layers of particles together. This causes the current in the film to change and light is emitted from the particles, an effect known as “electroluminescence”. The visible light is then detected by a camera.
The article goes on to guess at all sorts of potential applications such as detecting cancer. However, there’s no reason to believe this couldn’t be a huge boon for all of robotics, particularly something like touch sensors for a biomimetic prosthesis.
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