We propose a system for enabling auxiliary communication channels in which a node transmits a millimeter (mm) wave signal which is reflected off a deliberately vibrating surface of a second node and then received by the first node. Data sequences can be encoded in the modulation of the surface, and radar sensing techniques can be used to demodulate the reflected signal. Hence our system enables not only conventional sensing in terms of range, velocity, and orientation estimation but also allows for information to be conveyed by the sensed device. We introduce the design of a metasurface driven by an energy-efficient programmable piezo-electric actuator, detail suitable radar processing, and characterize the link performance of the kinetically induced channel at distances up to five meters. As this metasurface could be used for both mobile devices and infrastructure devices, we describe opportunities for enabling novel capabilities including secure device authentication and extended-range wireless sensing across multiple devices.