Improvements on a Sensitivity Adjustable 3-Axis Soft Skin Sensor with an Electromagnet

The sensitivity and measuring range of sensors are usually characteristics set before the production stage. However, sensors which are used as part of skin for robots would benefit from the ability to actively adjust their sensitivity during operation. Adjustable sensitivity implicitly broadens the range of operation of the sensor, which in turn is beneficial for interacting with both light and heavy objects. In this letter, we present the second iteration of a prototype sensor module that can be used as a skin sensor for robots. The sensor uses a flat electromagnet above a 3-axis magnetic sensor, separated by a layer of flexible material. The sensitivity of the sensor can be adjusted by changing the current that flows through the flat electromagnet. Each sensor module includes a microcontroller, providing digital output, multimodal and distributed sensing capabilities. Enhancements on the previous module version are discussed and implemented. Furthermore, we present results on temperature and magnetic field strength of the new coil board, and experiments on two possible different flexible materials to be used as a middle layer.