Wearable sensor measures fingertip forces without blocking touch
TacClip: a clip-on sensor measures dynamic contact forces without covering the fingerpads
Robotics
Summary
Measuring how your fingers feel forces usually requires covering the fingertip, which can stop you from feeling textures and temperature naturally. The authors developed TacClip, a small device that clips onto the fingernail instead of the fingertip pad, allowing you to keep feeling surfaces while tracking forces and vibrations. TacClip uses a special fiber sensor to detect finger pressure and subtle touch details, even underwater, without needing electronics on the finger pad itself. Tests showed it can measure finger pressing forces accurately and capture the vibrations when sliding on cloth or tape edges.
Fingertip deformationContact forcesVibrationsFiber Bragg GratingHand trackingVision-based trackingPolyimide stripsForce magnitudeWearable sensorsHaptic feedback
Authors
Yuqian Ye, Hao Li, Jingxi Xu, Haojun Feng, Seongheon Hong, Mark R. Cutkosky
Abstract
TacClip is a minimally encumbering wearable device for recording fingertip deformation caused by contact forces and vibrations. It can be combined with vision- or glove-based hand tracking systems that leave the fingertips uncovered and provides a measure of dynamic contact interactions, while leaving the finger pads exposed so that the user retains natural sensitivity to texture, friction, temperature, and fine surface features. The signal is produced by a Fiber Bragg Grating (FBG) embedded on a small plastic clip mounted over the fingernail. Optionally, for use with vision-based tracking, additional FBGs on polyimide strips can complement camera-based pose estimation. In finger pressing tests, TacClip estimates the force magnitude with typical errors below $0.5~\mathrm{N}$ over a $0$--$8~\mathrm{N}$ range. In tests of cloth handling and tape edge finding, we show that it captures the vibrations and dynamic events generated during exploratory sliding. With no electronics, TacClip can also be used submerged in water, while preserving bare finger contact.