Session: 06-01 Micro/Nano Systems for Human Machine Interaction-Part 1

Paper Number: 119229

119229 - Evaluation of Surface Wave Propagation Along Skin Surface During Haptic Actuation 

In recent years, novel actuator devices have provided various possibilities for implementing haptic interfaces in human-machine interaction. The most popular type of actuator used in smart phones or wearables for haptic feedback during human-machine interface is the linear resonant actuators (LRA) or eccentric rotating mass (ERM), which triggers mechanoreceptors for tactile sensations. However, a basic understanding of the mechanics associated with interfacing between vibrotactile actuators and the skin is essential when designing devices and interpreting sensory experiences. Despite this, the vibrations induced by these actuators on the palm remain to be elucidated with respect to the microscopic geometry of the skin surface and the mechanical properties of the palm tissue. This paper focuses on the influence of the anatomical structure of the palm including Palm flexion creases on the propagation of mechanical waves elicited by vibrotactile actuator stimuli. We distributed vibration actuators at different locations according to the muscle and tendon structure as well as the palm flexion creases. Skin vibrations were measured with a laser vibrometer along different directions of across the palm surface. Our findings show that the propagation of vibrations at different locations in the palm plane is highly influenced by the palm flexion creases. The palm flexion creases and the knuckle prints distributed in the direction of skin wave propagation produced a substantial attenuation of the amplitude in terms of the vibration amplitude alone. This result can be observed from the vibration attenuation along the wave propagation direction we measured for the vibrators placed in different positions. We conclude that a better understanding of the propagation characteristics of the vibrations generated by the actuator on the skin surface is essential to design effective and accurate haptic feedback interfaces in human-computer interaction. Given the complex dependence of skin vibrations on surface microgeometry and fingertip biomechanics, this understanding can lead to a more efficient use of vibratory actuators.

Presenting Author: Qiutong Liu The Hong Kong Polytechnic University

Presenting Author Biography: Miss Qiutong Liu joined the Hong Kong Polytechnic University in 2021 as a Ph.D. student.