"Compared with the previous works (see references 1-3 below), this smart skin reduces the number of electrodes remarkably," Zhang points out. "This helps a lot to reduce the complexity of the signal processing circuit. Although using less electrodes, our smart skins achieve 1.9 mm resolution, much better than previous results."
She notes that, compared with digital smart skins which have been studied extensively, analogue smart skins still need more in-depth study.
"Analogue smart skins have obviously advantages at resolution and energy consumption," she says. "I hope our work can draw more attention to the field of analogue smart skins. Furthermore, it will contribute to the areas of artificial intelligence and portable electronics as the self-powered high-resolution sensor offers a solution for smart skin applications."
Use of smart skin on an artificial hand. (a) Photograph of an artificial hand covered by two-dimensional analogue smart skins on the curved back of the hand and one-dimensional analogue smart skins on the middle finger. (b) Voltage output when a honey bee approaches and leaves the two-dimensional smart skin swiftly. (c,d) Voltage ratios of electrodes a-d. (e) Voltage output when the two-dimensional smart skin on the artificial hand is touched. (f) Location result of analogue smart skins. The testing point is (2.50, 2.50), and the result is (2.53, 2.50), with a slight deviation of only 0.3 mm.
Going forward, the team will work on the stretchability of their smart skin (the current version is not stretchable) and on improving the resolution. According to the team, due to the theoretically infinite resolution, there still is plenty of room to improve on the current performance. Furthermore, they will try to integrate more sensing parameters as well as signal transmission in the design.
Last but not the least, they will explore approaches to shield the smart skin from environmental interference, which is critical for practical applications.
Zhang notes that the current device design provides opportunities for including additional sensing capabilities such as temperature, contact velocity, or gas composition.
Page 2 of 2