Touchscreens with Tactile Feedback
Touch-sensitive screens (touchscreens) simplify direct control of electronic devices. Since the immediately intuitive input of a command by a finger is especially simple and user-friendly, more and more electronic devices such as cell phones and navigation devices are being equipped with touchscreens. Compared to mechanical systems using a mouse and keyboard, the drawback of touchscreens until now has been that they do not offer any tactile feedback. Frequently, the user is not sure if contact with the touchscreen has actually initiated the desired function.
With its Bayfol Reflex, Artificial Muscle Inc., a subsidiary of Bayer MaterialScience, is offering an electroactive polymer-based system that provides fast and precise haptic feedback when operating touchscreens. The approach uses thin dielectric polymer films positioned between two electrodes. Upon application of a voltage, the film changes its thickness and expands in the surface direction. In this way, it is possible, for instance, to simulate the typical response of a mechanical key.
Electroactive polymers have very short response times, so that the tactile feedback is practically immediate. Since the deformation is proportional to the input current, the effect can be matched precisely to the particular requirements. The low power consumption of the polymer system is an extremely beneficial aspect in battery-operated devices. In addition, the electroactive polymers are characterized by reliability and durability. As the first commercial application of Bayfol Reflex technology, Mophie, Inc., Paw Paw/Michigan, is offering a so-called game grip under the name Pulse as an accessory for mobile devices.