The rich set of mechanoreceptors found in human skin offers a versatile engineering interface for transmitting information and eliciting perceptions, potentially serving a broad range of applications in patient care and other important industries. Targeted multisensory engagement of these afferent units, however, faces persistent challenges, especially for wearable, programmable systems that need to operate adaptively across the body. I present a miniaturized electromechanical structure that, when combined with skin as an elastic, energy storing element, supports bistable, self-sensing modes of deformation. Targeting specific classes of mechanoreceptors as the basis for distinct, programmed sensory responses, this haptic unit can deliver both dynamic and static stimuli, directed as either normal or shear forces. Systematic experimental and theoretical studies establish foundational principles and practical criteria for low-energy operation across natural anatomical variations in the mechanical properties of human skin. A wireless, skin-conformable haptic interface, integrating an array of these bistable transducers, serves as a high-density channel capable of rendering input from smartphone-based 3D scanning and inertial sensors. Demonstrations of this system include sensory substitution designed to improve the quality of life for patients in clinical trials of stroke and spinal cord injury.
Matthew T. Flavin is a postdoctoral researcher at Northwestern University, working with Prof. John A. Rogers. He received his M.S. and Ph.D. degrees in Electrical Engineering in 2021 from the Massachusetts Institute of Technology (MIT), and he received his B.S. in Electrical Engineering from the University of Illinois at Urbana-Champaign. He received the NIH Ruth L. Kirschstein Institutional National Research Service Award (T32) and the Draper Laboratory Fellowship. The vision for his independent research program is to develop powerful peripheral neural interfaces and mechatronic wearables that leverage advanced sensors and intelligent systems to address important and unresolved challenges in biomechanics and patient care.