Emerging Material Technologies for Haptics

Abstract

The sense of touch is involved in nearly all human activities, but information technologies for displaying tactile sensory information to the skin are rudimentary when compared to state‐of‐the‐art video and audio displays, or to tactile perceptual capabilities. Realizing tactile displays with good perceptual fidelity will require major advances in engineering, design, and fabrication. Research over several decades has highlighted the difficulties of meeting the required performance benchmarks using conventional devices, processes, and techniques. This has highlighted the important role that will be played by new material technologies that can bridge the electronic and mechanical domains. This must occur at the smallest scales, because of the great perceptual spatial and temporal acuity of the sense of touch. The requirements involved also furnish valuable performance benchmarks against which many emerging material technologies are being evaluated. This article highlights recent research and possibilities enabled through new material technologies, ranging from organic electronic materials, to carbon nanomaterials, and a variety of composites. Emerging material technologies are surveyed for the sense of touch, including sensory considerations and requirements, materials, actuation principles, and design and fabrication methods. A conclusion reflects on the main open challenges and future prospects for research in this area.

A Survey of Mid-Air Ultrasonic Tactile Feedback

“…It comprises of cutaneous inputs from the various types of mechanoreceptors in the skin and kinesthetic inputs from the muscles, tendons and joints. It provides updated information, e.g., on 3D shape and texture of objects, the position of the limbs, balance and the muscle stretch [4]. Mechanoreceptors have various densities in various body parts.…”

“…There are many surveys on haptics in general (e.g., [7], [58], [4]), but they all only shortly mention ultrasonic mid-air haptics. There are only two earlier surveys on the ultrasonic phased array haptics that we are aware of.…”

Virtual Texture Generated Using Elastomeric Conductive Block Copolymer in a Wireless Multimodal Haptic Glove

“…In particular, molecularly engineered materials whose surface energy, oxidation state, phase, and electrical and thermal conductivity can be changed in real time might allow for a wider gamut of tactile sensations than is now available. Moreover, materials that allow controllable deformation on smaller scales than is possible with conventional pneumatics will also accelerate discovery in the field . We stress, however, the importance of chemistry and the design of materials at the level of molecular structure.…”

“…Approaches to mimic the properties of surfaces fall under the category of “surface haptics,” which uses a variety of primarily electrostatic phenomena to add a tactile dimension of interaction with touch screens (e.g., demarcating the positions of icons or textures of items in e‐commerce) . Our group and others are exploring a complementary approach using stimuli‐responsive materials. An approach to haptics based on functional materials—especially stimuli‐responsive polymers—in haptics might provide access to sensations unavailable to approaches based on displacement alone.…”

“…Future work on the psychophysical aspects of the work includes the determination of perceptual thresholds and the extent to which sensations are confused. Moreover, advancements in approaches to fabrication—particularly in increasing the density of miniaturized actuators on flexible and stretchable substrates—will go hand in hand with the development of haptic devices capable of increased realism …”