Chemical and Biomolecular Engineering Research and Publications


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This paper was originally published inthe "Science " Magazine VOL.312,Issue 5779 ,pp 1501-1504 on 9 June 2006.All the copy rights © of this paper belongs to American Association for the Advancement of Science(AAAS). The publishers version of this article can be found at Science 2006 Any further information about this paper can be found at AAAS


Touch (or tactile) sensors are gaining renewed interest as the level of sophistication in the application of minimum invasive surgery and humanoid robots increases. The spatial resolution of current large-area (greater than 1 cm2) tactile sensor lags by more than an order of magnitude compared with the human finger. By using metal and semi conducting nanoparticles, a 100-nm-thick, large-area thin-film device is self-assembled such that the change in current density through the film and the electroluminescent light intensity are linearly proportional to the local stress. A stress image is obtained by pressing a copper grid and a United States 1-cent coin on the device and focusing the resulting electroluminescent light directly on the charge-coupled device. Both the lateral and height resolution of texture are comparable to the human finger at similar stress levels of 10 kilopascals.