A Low-Cost Modular System of Customizable, Versatile, and Flexible Tactile Sensor Arrays

The key role of tactile sensing for human grasping and manipulation is widely acknowledged, but most industrial robot grippers and even multi-fingered hands are still designed and used without any tactile sensors. While the basic design principles for resistive or capacitive sensors are well known, several factors keep tactile sensing from large-scale deployment - high sensor costs, short lifespan, poor reliability, difficult production processes, a lack of suitable software and tools for system integration, and the unique requirement for tactile sensors to conform to application-specific shapes. In this work, we describe a very simple but efficient approach to design low-cost resistive matrix sensors, where sensor layout and geometry, taxel-size, and measurement sensitivity can be customized over a wide range. Sensor assembly needs nothing more than a hobby cutting plotter for precise cutting of aluminum tape and Velostat foils, as well as adhesive plastic tape. Our electronics combines transimpedance amplifiers with common Arduino microcontrollers, supporting standard communication protocols, and using either cabled or wireless data transfer to the host. We present three different application examples and sketch our ROS software for sensor calibration and visualization. All parts of our project, including detailed building instructions, bill-of-materials, electronics, and firmware are available open-source.