Magnetic Nanocomposite Surface for Tactile Sensing
The need of efficient methods for providing environmental perception leads to an increase in the development of tactile sensor concepts applicable to advanced robots, surgical instruments etc. Tactile sensors play a central role in artificial skins, which are supposed to mimic the ability of sensing touch like in humans. This complex task requires providing solutions for a variety of aspects ranging from sensitivity, durability, power consumption, scalability, biocompatibility, flexibility and stretchability to name a few.
The magnetic nanocomposite surface for tactile sensing is a bio-inspired concept that utilizes micro-scale pillars, which are found in various forms as cilia receptors in nature. In the same way as the cilia receptors, the micro pillars are sensitive to bending. They are made of a magnetic nanocomposite consisting of permanent magnetic nanoparticles and polydimethylsiloxane. This material combination provides high bending flexibility, chemical corrosion resistance, biocompatibility and a magnetic field. Magnetic sensors are integrated into the substrate of the nanocomposite surface to detect the magnetic field of the pillars. When the pillars are bent, the change in magnetic field is registered by the magnetic sensors. The nanocomposite surface features a high performance in terms of sensitivity, power consumption and versatility. Forces of less than 100 μN can be detected with a power consumption that can be below 100 nW, and the surface works in air as well as water. The properties of the nanocomposite surface can be easily tuned by the nanoparticle concentration and the geometric parameters of the pillars. The surface can be realized on rigid as well as flexible substrates and is able to perform a variety of measurement tasks like force, texture, movement of objects or fluid flow.