A New Soft Force Sensor using Blended Silicone-Magnetic Powder

In this paper, a new soft sensor is introduced in order to measure normal forces for use in soft robotics applications. Soft sensors and actuators usually have high flexible structures and therefore require elements which are compatible with this flexibility. We introduce a new approach to achieve more desired softness and flexibility specifically for soft magnetic force sensors. For this purpose, magnetic powder is used instead of a solid piece of magnet. Therefore, the Hall Effect sensor detects magnetic flux density induced by magnetic powder blended with soft silicone rubber. Using magnetic powder provides flexibility and soft behavior to the sensor. In addition, compared with solid magnet designs, the effective working rang is expanded. Three different structural parameters i.e. powder density, magnetic part diameter and height of the sensor are studied in order to choose the most proper design to get the best performance depending on the expected characteristics behavior for the sensor. It is shown by experimental results that different desired measurement range as well as sensitivity can be achieved by appropriate selection of these three parameters, which makes the sensor usable for many low-cost soft robotics applications.