Fingerpad deformation during robot-controlled tactile stimulation

The sense of touch allows us to manipulate objects with exquisite dexterity. The tactile receptors in the skin acquire information about the mechanical interactions between the fingertip and the objects during manipulation by transducing local skin deformations. This information is essential for the fine coordination of the prehension forces. However, what is the information provided to the brain by the tactile system during manipulation and how does the brain uses this information to coordinate finger forces remains unclear. This thesis presents methods to quantify skin deformation during tangential loading of the skin, closely mimicking object manipulation. To that end, we use a custom-made robotic platform able to apply controlled normal and tangential force profiles to the fingerpad using a flat transparent plate of glass. At the same time, images of the finger pad and image processing techniques are used to quantify the skin displacement field and to consequently derive skin strains.