CubeSense: Wireless, Battery-Free Interactivity through Low-Cost Corner Reflector Mechanisms

Ubiquitous computing systems rely on ubiquitous methods to sense user interactions, which have manifested in our daily environments as physical buttons, switches, sliders, and beyond. These conventional controllers are either wired, which eliminates flexible deployments, or powered by batteries that require user maintenance. Additionally, built-in wireless communications such as Wi-Fi, Bluetooth, and RFID add up to the total cost. All aforementioned constraints prevent truly ubiquitous interactions from intelligent environments such as smart homes, industry 4.0, precision farming, and a wider range of Internet-of-Things (IoT) applications. We present CubeSense, a wireless and battery-free interactive sensing system which encodes user interactions into radar cross section (RCS) of corner reflectors. Through careful designs of corner reflector mechanisms, CubeSense achieves robust accuracies with controllers made of ultra-low-cost plastics and metal films, resulting in a total cost of around only 20 cents per unit.