Fig. 3: Flexible sub-mm tactile actuator array for tactile rendering.
From: Highly pixelated, untethered tactile interfaces for an ultra-flexible on-skin telehaptic system
a Image of a single actuator unit on a fingertip, scale bar is 2 mm. b Optical microscope image of sub-mm tactile actuator. Multi-stack piezoceramic block is miniaturized for high-resolution tactile rendering, scale bar is 200 μm. c magnified optical microscopic image of multi-layered piezoceramic actuator, scale bar is 100 μm. d Schematic of multi-layered piezoelectric actuator and its operation mechanism. e FEM simulation of stress distribution in flexible actuator arrays that have 3 different substrate thickness during bending. f side view of FEM simulation. g Sum of stress at the interface between actuator and substrate during bending. Stress is relieved by chessboard/diagonal arrangement (solid line) compared to square arrangement (dashed line). h output performance of a single actuator under increased pressure preloads while input voltage is applied from 5 to 60 Vpp. i Frequency dependence of single actuator under pressure loading. Red line show output displacement under pressure loading while the frequency is changed from 100 to 1000 Hz. Blue line shows displacement under pressure loading while input voltage is changed from 5 to 60 Vpp. Inset is a magnified plot in frequency range 200 to 500 Hz. j Amplitude modulation of sub-mm piezo actuator for expression of static pressure feeling. Low frequency of 1–10 Hz has been demonstrated with a carrier frequency of 300 Hz.
