In FLASHED, we will discover a new technology in the field of flexible displays. A major problem of flexible displays is still the lack of interactivity, because none of the market-ready touch solutions are flexible (bendable). Therefore, one major goal of FLASHED is the development of novel, flexible touchscreen solutions, covering aspects like cost-effectiveness (all-printed), sustainability (material recycling and end-of-life disposal) and energy-efficiency (self-sustaining sensor arrays). Moreover, the FLASHED project puts strong emphasis on user-friendly interfaces. The FLASHED device itself consists of a flexible display, a touchscreen layer based on a pressure sensing touch array (utilizing ferroelectric polymers) and a haptic/acoustic feedback layer based on a relaxor ferrolectric material.
Sonoflex is a flexible, textile dynamic speaker made without using a permanent magnet. Our design consists of two flat spiral coils, stacked on top of each other, and is based on an isolated, thin enameled copper wire. Our approach allows for thin, lightweight, and flexible embroidered devices and does not require high voltage as in electrostatic speakers. We show how Sonoflex can be designed and fabricated, and evaluate its acoustic properties with respect to manufacturing parameters, such as size, turn counts, turn spacing, and substrate materials. We are able to produce audible sound with a broad frequency range of 1.5 kHz – 20 kHz with a 50 mm diameter implementation.