Biological sensors exhibit exquisitely high sensitivity, large dynamic range, and robust and efficient signal reconstruction. They accomplish these even with imperfect and noisy data. Further, most biological sensors are employed as flexible sensor skins consisting of two dimensional, high density, multimodal sensor array. The overarching engineering objective of the proposed work is to develop a flexible, multimodal sensing skin for the sense of touch that exploits biologically inspired principles to achieve high sensitivity, wide dynamic range, and an advanced, highly-efficient signal processing capability. Specifically, we will focus on developing artificial glabrous and hairy touch-sensitive skin ? parallel arrays of multimodal tactile sensors ? along with companion signal processing algorithms. A glabrous skin is largely smooth and consists of normal and shear contact sensors, whereas a hairy skin further consists of exposed hairs for proximal touch sensing. We plan to test-bed the sensors and algorithms in one application: smart, sensorized catheter tips for cardiac surgery procedures (e.g., tissue ablation, internal space mapping, ECG recording), with intended benefits of increased accuracy, reliability, and speed. The proposal seeks transformative interdisciplinary research in the following major areas: (1) The proposal team will develop a silicon-polymer hybrid, flexible sensing skin with multimodal sensor integration by leveraging existing expertise of artificial haircell sensors and multimodal tactile sensors. (2) The team will develop a radical multimodal tactile sensor skin, mimicking glabrous and/or hairy skin, consisting of artificial hairs (whiskers) and other tactile sensing modalities (normal and shear contact, temperature, etc). (3) The team will seek biological inspirations at many levels to increase the sensitivity, widen the dynamic range, and enhance speed and robustness of downstream signal processing. (4) The team will creatively explore the use of active sensing ? sensors that sense the properties of surroundings through movement and active engagement, rather than passive interfaces. (5) The team will perform cutting edge research on signal processing, to face the challenge of massive sensor data and multimodal sensor informatics fusion. Here, bioinspiration will be sought by investigating a model system, early signal-processing stages of the rodent whisker (vibrissal) touch sensor.
