Armband with Soft Robotic Actuators and Vibrotactile Stimulators for Bimodal Haptic Feedback from a Dexterous Artificial Hand

Abstract

The haptic sense relies upon a plurality of receptors and pathways to produce a complex perceptual experience of contact, pressure, taps, vibrations and flutters. This complexity is yet to be reproduced in haptic feedback interfaces that are used by people controlling a dexterous robotic hand, be it for limb-absence or teleoperation. The goal of the present bimodal haptic armband is to convey both low-frequency pressure changes and high-frequency vibrations from a dexterous robotic hand to a human's upper arm, so as to guide his/her control of the artificial limb. To that end, we design and manufacture four novel soft robotic armbands combining inflatable air chambers and vibrotactile stimulators. We develop control systems for both pathways. We conduct a series of benchtop tests to determine the pneumatic and vibrotactile performance and select from competing designs and materials. We test two of the resulting bimodal haptic armband on human subjects and confirm their ability to use both aspects of this haptic information. Arguing that dexterous artificial hands are presently not used to their fullest capability by the dearth of haptic information in users, this work aims to achieve a more realistic tactile experience for a fluent, more natural usage of robotic artificial hands.

Simulated robotic device malfunctions resembling malicious cyberattacks impact human perception of trust, satisfaction, and frustration

“…Both layers were bonded together using a thin layer of Dragon-Skin 30. Full details about the design and manufacturing of the soft actuator armband can be found in the study by Abd et al, 20 where a psychophysics study demonstrated that human subjects could reliably discriminate between six discrete levels of pressure applied by the soft robotic armband.…”

“…[15][16][17] The potential for malicious attacks causing artificial hand malfunction is one motivation of this article, which makes use of an i-limb prosthetic hand 18 that has been customized with tactile sensors in the fingertips 19 to enable an artificial sense of touch from a soft robotic armband worn by human test subjects. 20 Tactile information plays an important role when interacting with or manipulating different objects. [21][22][23] When amputees lose their hands, this afferent pathway of information is severed, and it can be difficult for them to control any object accurately without haptic feedback, using vision alone.…”

“…[34][35][36] Passively powered pneumatic actuators have also been previously used to map the robotic fingertip forces to the residual limb of amputees, 36 A soft robotic armband with pump-driven pneumatic chambers for haptic feedback has also been designed in the past, which was previously tested with 10 human subjects who were able to recognize six discrete air pressure levels (10-35 kPa with 5 kPa increments) corresponding to six levels of robotic fingertip force. 20 In this new study, the previously designed soft robotic armband 20 will be used by 10 people who operate an i-limb prosthetic hand mounted on a robotic arm that was programmed to periodically malfunction in ways that could potentially be caused by malicious attacks on the artificial limb control system. The trust, satisfaction, and frustration 37 of the subjects were surveyed as they operated the robotic system under multiple normal and abnormal scenarios to see the impact that potential malicious attacks could have on these metrics, which could strongly impact whether or not amputees reject usage of their prostheses.…”

“…15 –17 The potential for malicious attacks causing artificial hand malfunction is one motivation of this article, which makes use of an i-limb prosthetic hand 18 that has been customized with tactile sensors in the fingertips 19 to enable an artificial sense of touch from a soft robotic armband worn by human test subjects. 20…”

“…34 –36 Passively powered pneumatic actuators have also been previously used to map the robotic fingertip forces to the residual limb of amputees, 36 A soft robotic armband with pump-driven pneumatic chambers for haptic feedback has also been designed in the past, which was previously tested with 10 human subjects who were able to recognize six discrete air pressure levels (10–35 kPa with 5 kPa increments) corresponding to six levels of robotic fingertip force. 20…”