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Cross-cutting Challenges - Theme 1: Interactive Discussions
Cross-cutting Challenges
California East
Arm-Worn Tactile Displays
(Max Planck Institute for Intelligent Systems, Germany)
Abstract: Fingertips and hands captivate the attention of most haptic interface designers, but humans can feel touch stimuli across the entire body surface. Trying to create devices that both can be worn and can deliver good haptic sensations raises challenges that rarely arise in other contexts. Most notably, tactile cues such as vibration, tapping, and squeezing are far simpler to implement in wearable systems than kinesthetic haptic feedback. This interactive discussion will present a variety of relevant projects to which I have contributed, attempting to pull out common themes and ideas for the future. My interest in arm-worn tactile displays began when I was a doctoral student with Günter Niemeyer at Stanford University. Motivated by the goal of enabling a surgeon to feel contact along the slender instruments one teleoperates in an Intuitive Surgical da Vinci system, I embedded eight eccentric- rotating-mass (ERM) motors in a line inside a long glove and drove them to simulate contact at a stationary location in space. The first NSF grant I received as an assistant professor at the University of Pennsylvania built somewhat on that early glove prototype. Working with collaborators from Moss Rehabilitation Research Institute, Karlin Bark and others on my team created a series of systems that sought to guide the motion of the wearer’s arm by controlling the vibrations delivered by eight ERM motors (four around the wrist and another four around the bicep). These vibrotactile cues aided users in performing simple but not complex arm motions. Frustrated by the slow response times and spatially diffuse sensations of ERM actuators, as well as the above system’s inability to guide wrist pronation/supination, Andrew Stanley and I created a suite of wrist-worn actuators that deliver tactile cues more like a person touching your wrist. We then compared these tapping, dragging, squeezing, and twisting actuators to a wrist band that contained six ERM motors. The best overall performance was enabled by the actuator that repeatedly taps on the subject’s wrist on the side toward which they should turn. Jeremy Brown and others recently employed the squeezing device to let the operator of a da Vinci robot feel the magnitude of the force the instruments are exerting. Finally, tactile displays can also be used to alter the wearer’s body perception. As a visiting masters student in my lab, Yosuke Kurihara wanted to make interactive games more compelling. He first recorded the vibrations that occur when a Puma 260 robot arm moved one of its gear-head-driven joints at different speeds. In his final system, the user wore a set of Tactile Labs Haptuators strapped to their joints plus an immersive VR headset that depicted a robot body that moved as they moved. The user felt robot vibrations corresponding to the present speed of each of their joints. Arm-worn tactile displays have great potential, but the design space is large and under-explored. I am currently interested in integrating motion sensing into garments and creating new wearable tactile actuation systems.


Time stamp: 2020-06-02T04:48:21+02:00