A Magnetic Soft Device for Tactile Haptic Actuation of the Fingertip

In this work, we introduce a novel haptic device composed of a wearable fingertip sheath, fabricated using an oleogel loaded with magnetic particles, and an external electromagnet. The sheath is actuated using the external magnetic field provided by the electromagnet, which is equipped with a field-focusing pole piece. The oleogel composite used in this device has been optimized for the transfer of the magnetic force from the material to the skin to provide perceptible forces to the wearer. We compare our composite to composites created with materials commonly used in the literature and find the force transfer from our material, as measured by a force sensor, to be much greater when actuated under the same range of input voltages to the electromagnet. We also present a psychophysical user study that shows a linear relationship between this range of input voltages and perceptual magnitude. This result indicates that the device provides a range of tactile feedback that can be driven to a desired intensity of sensation through proportional voltage control.