Electrostatic footpads enable agile insect-scale soft robots with trajectory control

Abstract

Agility and trajectory control are two desirable features for robotics, but they become very challenging for soft robots without rigid structures to support rapid manipulations. Here, a curved piezoelectric thin film driven at its structural resonant frequency is used as the main body of an insect-scale soft robot for its fast translational movements, and two electrostatic footpads are used for its swift rotational motions. These two schemes are simultaneously executed during operations through a simple two-wire connection arrangement. A high relative centripetal acceleration of 28 body length per square second compared with existing robots is realized on a 65-milligram tethered prototype, which is better than those of common insects, including the cockroach. The trajectory manipulation demonstration is accomplished by navigating the robot to pass through a 120-centimeter-long track in a maze within 5.6 seconds. One potential application is presented by carrying a 180-milligram on-board sensor to record a gas concentration route map and to identify the location of the leakage source. The radically simplified analog motion adjustment technique enables the scale-up construction of a 240-milligram untethered robot. Equipped with a payload of 1660 milligrams to include the control circuit, a battery, and photoresistors, the untethered prototype can follow a designated, 27.9-centimeter-long “S”-shaped path in 36.9 seconds. These results validate key performance attributes in achieving both high mobility and agility to emulate living agile insects for the advancements of soft robots.

3D-Printed Miniature Robots with Piezoelectric Actuation for Locomotion and Steering Maneuverability Applications

“…Our robot demonstrated the potential to become a fully autonomous motion system, thanks to a large carrying capacity in combination with a lower estimated power consumption. It is worth pointing out that two untethered and autonomous sub-gram robots have already been reported: the work by Hollar et al [4] based on the MEMS technology featuring lower speeds and higher voltages, and the work by Liang et al [3], which required excitation voltages as high as 250 V. Finally, our proposed design demonstrated submicrometric positional resolutions competing only with the heavier steel-based systems.…”

“…A recent article by St. Pierre et al [2] highlighted the difficulties associated with the decrease in size of the robots concerning speed, control, and autonomy. The achievement of such miniature-sized robots would imply lower cost and accessibility to areas forbidden to larger robots [3].…”

Bioinspired soft electroreceptors for artificial precontact somatosensation

“…Biological systems provide ideal templates for state-of-the-art bionic electronics, typified by humanoid robotics ( 1 – 3 ), artificial receptors ( 4 , 5 ), actuators ( 6 ), and prosthetics ( 7 , 8 ). Analogous to mechanoreceptors of the skin, haptic sensors that are highly responsive to mechanical stimuli from surroundings have been deployed in various applications of autonomous devices ( 9 – 11 ), human-machine interfaces (HMIs) ( 12 – 14 ), and virtual/augmented reality ( 15 , 16 ). Nevertheless, haptic sensors operate only when they are physically touched or invaded ( 17 ) but fail to respond to precontact stimuli.…”

Neurorobotic approaches to emulate human motor control with the integration of artificial synapse

“…These inherent traits have inspired researchers to develop innovative biomimetic electronics aimed at integrating living organisms and electronic devices (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). In particular, biomimetic approaches for soft robots have enabled the development of soft prostheses that exhibit continuous and natural deformation with large compliance (11)(12)(13)(14)(15). Owing to these characteristics, such devices can easily adapt to different environments while safely interacting with humans (16)(17)(18).…”