Shaping Compliance: Inducing Haptic Illusion of Compliance in Different Shapes with Electrotactile Grains

Compliance, the degree of displacement under applied force, is pivotal in determining the material perception when touching an object. Vibrotactile actuators can be used for creating grain-based virtual compliance, but they have poor spatial resolution and a limiting rigid form factor. We propose a novel electrotactile compliance illusion that renders grains of electrical pulses on an electrode array in response to finger force changes. We demonstrate its ability to render compliance in distinct shapes through a thin, lightweight, and flexible finger-worn interface. Detailed technical parameters and the implementation of our device are provided. A controlled experiment confirms the technique can (1) create virtual compliance; (2) adjust the compliance magnitude with grain and electrode parameters; and (3) render compliance with specific shapes. In three example applications, we present how this illusion can enhance physical objects, elements in graphical user interfaces, and virtual reality experiences.