GelTouch: Localized Tactile Feedback Through Thin, Programmable Gel

We present GelTouch, a gel-based layer that can selectively transition between soft and stiff to provide tactile multi-touch feedback. It is flexible, transparent when not activated, and contains no mechanical, electromagnetic, or hydraulic components, resulting in a compact form factor (a 2mm thin touchscreen layer for our prototype). The activated areas can be morphed freely and continuously, without being limited to fixed, predefined shapes. GelTouch consists of a poly(N-isopropylacrylamide) gel layer which alters its viscoelasticity when activated by applying heat (>32 C). We present three different activation techniques: 1) Indium Tin Oxide (ITO) as a heating element that enables tactile feedback through individually addressable taxels; 2) predefined tactile areas of engraved ITO, that can be layered and combined; 3) complex arrangements of resistance wire that create thin tactile edges. We present a tablet with 6x4 tactile areas, enabling a tactile numpad, slider, and thumbstick. We show that the gel is up to 25 times stiffer when activated and that users detect tactile features reliably (94.8%).

@inproceedings{10.1145/2807442.2807487,
 author = {Miruchna, Viktor and Walter, Robert and Lindlbauer, David and Lehmann, Maren and von Klitzing, Regine and M"{u}ller, J"{o}rg},
 title = {GelTouch: Localized Tactile Feedback Through Thin, Programmable Gel},
 year = {2015},
 isbn = {9781450337793},
 publisher = {Association for Computing Machinery},
 address = {New York, NY, USA},
 url = {https://doi.org/10.1145/2807442.2807487},
 doi = {10.1145/2807442.2807487},
 booktitle = {Proceedings of the 28th Annual ACM Symposium on User Interface Software & Technology},
 pages = {3–10},
 numpages = {8},
 keywords = {thermoresponsive hydrogel, tactile feedback},
 location = {Charlotte, NC, USA},
 series = {UIST '15}
 }