Technology Breakthrough for Digital Communication of Touch Signals
Researchers at the University of California, San Diego have developed technology that could pave the way for digital systems to record, store, and replay information through touch. "Touch was largely bypassed by the digital revolution, except for touch-screen displays, because it seemed too difficult to replicate what analog haptic devices – or human touch – can produce," says electrical and computer engineering professor Deli Wang. In addition to uses in health and medicine, the communication of touch signals could have far-reaching implications for education, robotics, gaming, and military applications. The researchers demonstrated the electronic recording of touch contact and pressure using an active-matrix pressure sensor array made of transparent zinc-oxide, thin-film transistors. The companion tactile feedback display used an array of diaphragm actuators made of an acrylic-based dielectric elastomer with the structure of an interpenetrating polymer network. The polymer actuators' actuation - the force and level of displacement - are modulated by adjusting both the voltage and charging time.
Transcript
00:00:01 this movie is a demonstration of our integrated touch pressure sensing and reproduction system all of the processing is done in real time the top left image shows our pressure sensitive TFT array you can see small Allen wrenches with a non-conductive polymer coating pressing on the array inducing pressure the pressure is detected in the TFT array in form of a current increase
00:00:27 on a specific TFT in the array this information is measured by a circuit described in the paper and supplemental materials and then transmitted to a PC the PC running a mat lab program which processes the TFT data obtains a 2d surface plot of pressure shown in the bottom half of the screen please note that stray points are caused by measurement noise and that
00:00:54 column 4 and 8 do not respond to pressure due to fabrication faults this splits the 2D surface plot when column 4 is pressed upon the surface plot is processed to obtain a graph of local maximum points shown in the bottom right these points correspond to the TFT array positions of Applied pressure the local Maxima points are then sent from the PC to the
00:01:18 actuator array system reproducing the inputed pressure this video shows successful one and two point pressure sensing and reproduction