Touch Sensitivity of Objects Based on Surface Acoustic Waves

摘要

With the mode conversion effect of surface acoustic waves, a touch sensitivity of solid plates can be achieved without affecting the front side but by attaching transducers to the backside of the plate. By thinning the region of the surface acoustic wave transmission to a thickness smaller than the wavelength, a large touch sensitivity of about 70% has been achieved at different materials such as ceramics, metals and plastics. This is accompanied by mode splitting and dispersion, which may provide an access for internal referencing with respect to aging and temperature influences. Prospectic applications of this touch sensing concept are tiles with switching functions in bathrooms or touch control panels at medical equipments, in kitchens or in cars.