Multimodal, High-Resolution Imaging System Based On Stimuli-Responsive Polymers

Providing realistic impressions about a virtual ambient for interaction with human's auditory, visual, and tactile perception is one of the core challenges of modern imaging systems. However, particularly tactile displays with high spatial resolution implemented as a large-scale integrated microelectromechanical system are not yet realized. Here, we report on a multimodal display with thousands of actuator pixels, which generates both visual and tactile impressions of a virtual surface. The fully polymeric, monolithically integrated device consists of an actuator array made from poly(N-isopropylacrylamide). This material is a stimuli-responsive, particularly temperature-sensitive hydrogel. Controlling the actuator temperature via an optoelectrothermic interface between an upper and lower temperature the actuator can be switched from the swollen to the shrunken state (volume change up to 90%) in several hundred milliseconds. To benefit from this highly dynamic behaviour it is necessary to use a control unit which provides the required temperature changes also in the range of milliseconds. For characterizing the time behaviour of our optoelectrothermic control unit we use the change in transparency of PNIPAAm caused by the phase transition. In this paper we preferably discuss the time behaviour of the display devices.