Dynamically adjustable haptics for 3D-printed user interfaces via metamaterials augmented with force-transmission lines

Haptic feedback has wide applicability in devices used by humans. Mobile phones, cars, medical devices, and games all provide useful information via tactile and kinesthetic channels. Recently the possibility has arisen of 3D printing entire working devices— including the user interface—but haptic feedback in printed devices remains underexplored due to the lack of printable mechanisms that offer fine-grained runtime adjustability of haptic sensations. The objective of the proposed project is to develop 3D-printed mechanisms that offer dynamically adjustable tactile and kinesthetic haptic feedback. The idea is to modify the force-responsive properties of mechanical metamaterials by manipulating the flexibility of individual cells within the material. By doing so, we hope to create an entirely new class of haptic device which can dramatically vary its feel during use. Our approach is to develop a new type of 3D printer capable of automatically embedding line material (e.g., wire or tubing) at print time, without user intervention, throughout the 3D structure of a printed object. We can then tune the properties of targeted cells—for example, softening certain cells in a thermoplastic metamaterial via embedded nichrome wire—to update the bulk tactile or kinesthetic properties of the material.