Researcher(s)
- Benjamin Azevedo, Electrical Engineering, University of Delaware
Faculty Mentor(s)
- Nathan Lazarus, Electrical & Computer Engineering, University of Delaware
Abstract
Current technology lets users interact with devices primarily through sight and hearing, which has led to many ways of controlling these devices, but using the sense of touch remains a significant challenge. That being said, a device such as a piece of clothing that provides sensory feedback would let users operate devices with more control, potentially unlocking many new technology applications. My research focused on designing a wearable device that provides the wearer with tactile feedback using individual vibrating actuators. The actuators vibrate by applying an alternating current through a conductive coil, which produces a magnetic field. A small magnet is then suspended in a silicone plate next to the coil, and this causes the magnet to oscillate, leading to the vibration of the silicone plate. To obtain strong vibrations while maintaining power efficiency, the highest vibration amplitude, or the mechanical resonance, has to fall in the range of 100-300 Hz, as this is the frequency range that human skin is the most sensitive to. A capacitive proximity sensor was used to detect the plate’s displacement as it vibrated, and the plate’s height and radius were adjusted to target a resonance frequency between 100 and 300 Hz. It was discovered that a silicone plate with a radius of about 15mm and a height of about 9.5mm results in a resonant frequency of about 190 Hz when a sinusoidal wave with an amplitude of 750 mV was applied to a copper coil with ten turns underneath the plate. This falls within the human-sensitive range, and it means that less power is necessary for our device to produce adequate actuator vibrations. Future research would involve constructing an array of actuators with these established geometric parameters so that specific vibrational patterns could be produced with the proper control logic.