  Vision-based tactile sensors that can measure 3D geometry of the contacting
objects are crucial for robots to perform dexterous manipulation tasks.
However, the existing sensors are usually complicated to fabricate and delicate
to extend. In this work, we novelly take advantage of the reflection property
of semitransparent elastomer to design a robust, low-cost, and
easy-to-fabricate tactile sensor named DTact. DTact measures high-resolution 3D
geometry accurately from the darkness shown in the captured tactile images with
only a single image for calibration. In contrast to previous sensors, DTact is
robust under various illumination conditions. Then, we build prototypes of
DTact that have non-planar contact surfaces with minimal extra efforts and
costs. Finally, we perform two intelligent robotic tasks including pose
estimation and object recognition using DTact, in which DTact shows large
potential in applications.
