WiForce: Wireless Sensing and Localization of Contact Forces on a Space Continuum

Abstract

Contact force is a natural way for humans to interact with the physical world around us. However, most of our interactions with the digital world are largely based on a simple binary sense of touch (contact or no contact). Similarly, when interacting with robots to perform complex tasks, such as surgery, richer force information that includes both magnitude and contact location is important for task performance. To address these challenges, we present the design and fabrication of Wi-Chlorian 1 , which is a 'wireless' sensor that can be attached to an object or robot, like a sticker. Wi-Chlorian's sensor transduces force magnitude and location into phase changes of an incident RF signal, which is reflected back to enable measurement of force magnitude and contact location. Wi-Chlorian's sensor is designed to support wideband frequencies all the way up to 3 GHz. We evaluate the force sensing wirelessly in different environments, including through phantom tissue, and achieve force accuracy of 0.3 N and contact location accuracy of 0.6 mm.