Researchers in the UCLA Department of Materials Science and Engineering have developed a high resolution, refreshable, and low-cost pneumatic tactile interactive device with a compact structure, single fluidic reservoir, and high actuator density that exerts large stroke and provides high blocking force.
Tactile interactive devices are often displays that provide normal indentation to a user’s fingertips by vertically moving miniature pins in response to electric or pneumatic signals. The movement of the miniature pins reproduces shapes, patterns, or textures which the user can identify. Such devices have a broad range of applications, from creating haptic feedback to reproducing Braille patterns for users who are visually impaired. Despite the importance of tactile interactive devices, their presence in the marketplace has been limited due to technological barriers and high costs. Specifically, the actuators in many tactile devices are bulky and do not produce sufficient pin displacement or blocking force to return the pins to their original positions. Additionally, devices operating in response to an electric signal typically require a high voltage, which poses danger to the user. While pneumatic tactile devices address some of the foregoing limitations, pneumatic devices often have complex structures, require multiple pneumatic reservoirs, and do not produce the level of pin displacement required for Braille readers.
Researchers in the UCLA Department of Materials Science and Engineering have developed a high resolution, refreshable, and low-cost pneumatic tactile interactive device with a compact structure, single fluidic reservoir, and high actuator density that exerts large stroke for pin displacement and provides high blocking force. The device uses a bistable electroactive polymer thin film and an electrode that can quickly perform stable actuation with a low voltage supply, allowing for safe operation of the device with fast response speeds. Specifically, the electrode can soften the polymer film at 30 V in less than one second. Furthermore, each actuator can be individually controlled by the application of local heating and pneumatic pressure.
Refreshable tactile display; tactile interactive device; haptics; virtual reality; VR; bistable electroactive polymer; electronic Braille readers