Design, Fabrication, and Demonstration of Soft Thin-Film Actuators

Summary

Soft actuators can be used in the fabrication of soft robots and wearable devices. Their compliance enables them to maintain functionality even when deformed. Here, a protocol is presented to fabricate soft thin-film actuators and to demonstrate their application in crawling robots, soft robotic grippers, and haptic feedback interfaces.

Abstract

Soft actuators present promising properties regarding applications in soft robotics and human-machine interfaces. Especially when directly interfacing with human skin, soft thin actuators can match the mechanical coupling with human tissue. The exploration of improving the performance and robustness of soft actuators is crucial for the development of flexible devices. The demand for robust, flexible devices poses challenges to the performance and manufacturing methods of the actuators. The article illustrates techniques for the design and fabrication of soft thin-film actuators. These soft actuators are robust, and demonstrate potential in versatile scenarios. This protocol shows the potential of the thin-film actuators in three different applications. First, a crawling robot driven by soft thin-film actuators was fabricated. The robot is extremely robust. It can survive continuous hammering and remain functional even with three metal needles punctured through its body. Second, a soft robotic gripper, which can perform fine manipulation such as grasping a piece of paper without damaging it, was fabricated. Third, a haptic feedback device with a thin-film actuator was fabricated, which can provide touching feedback when interacting with human skin. This protocol demonstrates efficient fabrication processes for robust soft thin-film actuators, with various application potential for driving robust soft robotics.

Introduction

Compared to rigid motors, flexible actuators exhibit superior compliance and adaptability¹. They are widely used in the manufacturing of soft robots and sensors. Current types of soft actuators include pneumatic actuators², chemical fuel actuators³, hydraulic actuators⁴, shape-memory alloy (SMA) actuators⁵, dielectric elastomer actuators⁶, and electroactive polymers actuators⁷. The purpose of this research is to design a flexible actuator with a simple manufacturing process androbust performance. The ab....

Protocol

This protocol describes the fabrication phases of STFA and STFA-based crawling robots, soft robotic grippers, and haptic feedback interfaces. Figure 2, Figure 3, Figure 4, and Figure 5 show the step-by-step device fabrication process. The reagents and the equipment used in this study are listed in the Table of Materials.

1. Fabrication of a soft thin-film actuator

1. Design the interdigitated electrode pattern (Figure 2A).
2. Configure laser en....

Results

To demonstrate the proposed method, the protocol outlines the fabrication of prototype devices and the performance of functional validation. First, the manufacturing process of the STFA is detailed. Figure 2A shows the designed electrode pattern, comprising interdigitated electrodes terminating in connection pads for lead attachment. Figure 2E shows the completed STFA. During operation, applying a voltage across adjacent interdig.......

Discussion

Using this methodology, successful fabrication of STFAs was achieved, followed by a demonstration of their potential in three distinct applications. The STFA fabrication involves three critical steps: (1) appropriate 2D design: the electrode pattern geometry dictates the actuator's dimensions, while the quantity and dimensions of interdigitated electrodes critically determine the actuation performance; (2) reliable electrical interfacing: proper connection of the aluminum electrode layer to external leads is achieved.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
0.1 mm Double-sided tape	3M
0.8 mm Double-sided tape	3M	VHB
3D printer	Bambu	X1-Carbon
Airbrush	Clench	LP-131	The nozzle distance is 10 cm, the pressure is 15 psi, the angle is 45 to 60 degrees
AutoCAD	Autodesk
conductive adhesive	Jinshida	K-818
Dimethyl Formamide	Macklin	CAS 68-12-2
Laser cutter	Trotec	Q400	Engraving: power=55, speed=100, pulses per inch (PPI)/Hz = 1000 Cutting: power = 20, speed = 10, PPI/Hz = 1000
Micro automatic coating machine	BEVS	1818H	running speed = 2, scraper height = 0.7 mm
P(VDF-TrFE-CTFE)	Piezotech-Arkema
Polyethylene terephthalate (PET) foil with aluminum	Pinhao Technology
Robotic arm	Yeahbot	Am1
Silicone Elastomer Base	Sylgard	184
Single-sided tape	Deli