Let Your Body Move: A Prototyping Toolkit for Wearable Force Feedback with Electrical Muscle Stimulation

Electrical muscle stimulation (EMS) is a promising wearable haptic output technology as it can be miniaturized considerably and delivers a wide range of haptic output. However, prototyping EMS applications is challenging. It requires detailed knowledge and skills about hardware, software, and physiological characteristics. To simplify prototyping with EMS in mobile and wearable situations we present the Let Your Body Move toolkit. It consists of (1) a hardware control module with Bluetooth communication that uses off-the-shelf EMS devices as signal generators, (2) a simple communications protocol to connect mobile devices, and (3) a set of control applications as starting points for EMS prototyping. We describe EMS-specific parameters, electrode placements on the skin, and user calibration. The toolkit was evaluated in a workshop with 10 researchers in haptics. The results show that the toolkit allows to quickly generate non-trivial prototypes. The hardware schematics and software components are available as open source software.