Wireless Electrohydrodynamic Actuators for Propulsion and Positioning of Miniaturized Floating Robots

Abstract

Autonomous soft robots require compact actuators generating large strokes and high forces. Electro‐fluidic actuators are especially promising, they combine the advantages of electroactive polymers (low‐power consumption, fast response, and electrical powering) with the versatility of fluidic systems (force/stroke amplification). EHD (electrohydrodynamic) actuators are electro‐fluidic actuators whose motion results from charges being induced and accelerated in a liquid. They are extremely compact, silent, and low power (≤10 mW). They have been recently demonstrated in stretchable pumps and for the wireless propulsion of simple floating robots. This study demonstrates simultaneous wireless propulsion (2.5 mm s−1) and control of a 1 cm sized robot using a single DC signal. Voltage is applied between an electrode on the floating robot and a fixed one, both exposed to a dielectric liquid. Results support the underlying physical mechanism as EHD and characterize robot motion with different fluorocarbon liquids and voltages between 400 and 1800 V. Path following is demonstrated with a 3 × 3 array of electrodes. EHD actuators prove to be a simple, compact, low power alternative to magnetic and acoustic actuators for wireless powering and control of miniaturized robots, with applications in precision assembling at the micro/mesoscale, lab‐on‐chip, tactile displays, and active surfaces.

Electromechanical tensile test equipment for stretchable conductive materials

“…Fundamental research has been conducted to support advances in soft robotics. For example, studies on soft actuators (e.g., dielectric elastomer actuators (DEAs) [10] , [11] , [12] , [13] , soft electro-adhesion [14] , [15] , [16] , [17] , and stretchable pumps [18] , [19] , [20] ) provide a basic understanding of their characteristics. The primary strategy for developing soft robotics involves innovation in soft materials engineering, including materials synthesis, fabrication, and mechanical design [21] .…”

A DIY Fabrication Approach of Stretchable Sensors Using Carbon Nano Tube Powder for Wearable Device

“…Many soft actuator devices have already been developed. Examples of soft actuators include soft pneumatic actuators ( Faudzi et al, 2018 ; Mohamed et al, 2020 ; Tschiersky et al, 2020 ; Ying et al, 2020 ; Luo et al, 2021 ), soft electroadhesion ( Shintake et al, 2016 ; Guo et al, 2018 ; Okuno et al, 2019 ; Persson and Guo, 2019 ), stretchable pumps ( Cacucciolo et al, 2019 ; Seki et al, 2020 ; Shigemune et al, 2021 ), dielectric elastomer actuators (DEAs) ( Ji et al, 2019 ; Kajiwara et al, 2019 ; Minaminosono et al, 2019 ; Wang et al, 2019 ; Hiruta et al, 2021 ; Takagi et al, 2021 ; Wiranata et al, 2021 ; Zhao et al, 2021 ) a shape memory polymer ( Besse et al, 2017 ; Li et al, 2020 ; Miao et al, 2020 ; Scalet, 2020 ; Zeng et al, 2020 ), and gel actuators ( Maeda et al, 2007 , 2010 ; Hwang et al, 2019 ; Mao et al, 2020a , 2020b ; Zhang et al, 2020 ). To create an interface between soft actuators and human activity, the actuator must be equipped with an appropriate sensing method.…”

Fabrication of Soft and Wearable Electrostatic Generator Based on Streaming Electrification

“…They exhibit several desirable features such as light weight, flexibility, high responsiveness, low power consumption, high power density, low-noise operation, and low remaining heat. By ensuring a narrow electrode gap to generate a high electric field, actuators with various mechanisms have been developed, such as dielectric elastomer actuators, [2,3] electrohydrodynamic (EHD) fluid actuators, [4,5] and electrostatic adhesive actuators. [6,7] Not only are such actuators being used in microelectromechanical system devices due to the scale effect, but the recent development of prototyping technology has also led to applications such as macroscale artificial muscles.…”

“…Charge injection into an insulating fluid under a high electric field is the basis of the EHD phenomenon, which is used to induce a pressure in the case of fluid actuators. [4,5] During the phenomenon of EHD, fluid flow is generated by exposing an insulating fluid to a high electric field. The EHD phenomenon is governed by two mechanisms: conduction pumping and injection pumping.…”