Abstract
Recent advances in wearable computing ask for bendable and conformable electronic circuits and sensors, allowing an easy integration into everyday life objects. Here, we present a novel flexible tilt sensor on plastic using several conductive microspheres as gravity sensitive pendulum. The sensor provides a digital output of the measurement signal without the need for any additional electronics (e.g. amplifiers) close to the sensor. The sensor is fabricated on a free-standing polyimide foil with SU-8 photoresist defining the cavity for the pendulum. The pendulum consists of freely movable conductive microspheres which, depending on the sense of gravity, connect different electric contacts patterned on the polyimide foil. The shown tilt sensors with 4 and 8 contacts each achieve an angular resolution of 45° and 22.5°, respectively. The sensors exhibit a linear behaviour with a hysteresis of 10° max.