Direct Writing Corrugated PVC Gel Artificial Muscle via Multi-Material Printing Processes

Abstract

Electroactive PVC gel is a new artificial muscle material with good performance that can mimic the movement of biological muscle in an electric field. However, traditional manufacturing methods, such as casting, prevent the broad application of this promising material because they cannot achieve the integration of the PVC gel electrode and core layer, and at the same time, it is difficult to create complex and diverse structures. In this study, a multi-material, integrated direct writing method is proposed to fabricate corrugated PVC gel artificial muscle. Inks with suitable rheological properties were developed for printing four functional layers, including core layers, electrode layers, sacrificial layers, and insulating layers, with different characteristics. The curing conditions of the printed CNT/SMP inks under different applied conditions were also discussed. The structural parameters were optimized to improve the actuating performance of the PVC gel artificial muscle. The corrugated PVC gel with a span of 1.6 mm had the best actuating performance. Finally, we printed three layers of corrugated PVC gel artificial muscle with good actuating performance. The proposed method can help to solve the inherent shortcomings of traditional manufacturing methods of PVC gel actuators. The printed structures have potential applications in many fields, such as soft robotics and flexible electronic devices.

Carbon Nanotube-Doped 3D-Printed Silicone Electrode for Manufacturing Multilayer Porous Plasticized Polyvinyl Chloride Gel Artificial Muscles

“…Nonetheless, actuators consisting of PVC gels require thermoplastic electrodes, while most electrode materials do not meet this requirement. Wang has explored the printing of a PVC core via direct writing, but integrated printing of an electrode and core has not been investigated [19,20]. The research team proposed for the first time the integrated printing process of a shape memory polymer doped with CNT electrodes into the PVC gel core layer.…”

“…The research team proposed for the first time the integrated printing process of a shape memory polymer doped with CNT electrodes into the PVC gel core layer. However, due to the lack of thixotropic properties in the memory polymer-doped carbon nanotube electrode ink, it is difficult to achieve the printing of mesh electrodes, making it unsuitable for the rapid manufacturing of multi-layer mesh PVC gel structures [19].…”

Deformation theory and nonlinear dynamic behavior of PVC gel actuators

“…And in his following research [22], the performance of the actuator was improved by adding ionic liquid additives, and an improved model was developed to describe the role of these additives. When a stable external excitation such as a DC voltage is applied, the PVC gel undergoes stable deformation, and the electrically induced deformation can eventually reach a stable value [23]. When an alternating current (AC) voltage is applied, PVC film generates dynamic nonlinear vibrational deformations [24,25].…”

Material Extrusion of Helical Shape Memory Polymer Artificial Muscles for Human Space Exploration Apparatus

“…Despite their advantages, exoskeletons using pneumatic artificial muscles require heavy pumps to drive the system and compressed air that could be better allocated for sustaining astronauts, making them costly for transport and resource inefficient for human space exploration. Shape memory alloy (SMA) [ 8 , 9 ] and shape memory polymer (SMP) [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ] based artificial muscles do not require heavy motors or pumps to actuate. Instead, shape memory materials use external stimuli, such as temperature, magnetic field, or pH level changes, to alter the shape and/or mechanical properties of a structure.…”

“…By applying different crosslinking mechanisms, such as temperature change or ultraviolet radiation (UV), the deposited layer is solidified with the enhanced mechanical stiffness necessary to support the subsequent layers. Thus, complex 3D structures, such as helical SMP artificial muscles, can be built layer-by-layer by moving the printhead vertically between layers [ 19 , 20 , 21 , 22 ]. To print artificial muscles through FDM, support materials must be created in the overhanging sections of the helix profile, resulting in large quantities of material waste [ 27 ].…”