An Elastomer-based Flexible Optical Force and Tactile Sensor

Tactile and force sensing devices that are capable to interactively explore the external environment have attracted a lot of research interest. Optical-based tactile sensors are becoming popular because they do not suffer from electromagnetic interference and because improved signal processing techniques enable intelligent sensor data classification. However, there is still no implementation of a sensor that measures both force and tactile information concurrently in an efficient manner in terms of material efficiency. In this research, we present a novel design for an elastomer-based tactile and force sensing device that senses both information within one elastomer. In addition, the tactile information is measured in the form of pressure distribution from the surface of objects. The proposed sensor has a soft and compliant design employing an opaque elastomer. The optical sensing method is used to measure both force and tactile information simultaneously based on the deformation of the reflective elastomer structure and a flexure structure. Here, we present the fabrication and development principles of the overall sensor. The experimental evaluation shows that the prototype is capable of sensing normal forces up to 70 $\mathbf{N}$ with an error of 6.6%.