Thermoplastic electroactive gels for 3D-printable artificial muscles

Abstract

3D-printable artificial muscles have only recently garnered interest, and few 3D-printed artificial muscles have been demonstrated. In this article, we introduce the concept of thermoplastic electroactive gels, new smart materials that can be fabricated simply and rapidly by heating, overcoming the limitations of previous dangerous and time-consuming solvent-based manufacturing methods, and enabling hot-pressing, melt-recycling, extrusion and 3D-printing. We present and characterise a new example material, PVC-DIDA (polyvinyl chloride and diisodecyl adipate) gel and demonstrate multi-layer PVC-DIDA gel artificial muscles. Finally, the extrudability of PVC-DIDA gel is confirmed, and an artificial muscle made from extruded electroactive gel is presented. The electroactivity and extrudability of these thermoplastic gels highlights them as excellent candidate materials for 3D-printing artificial muscle structures.

Characterisation of Self-locking High-contraction Electro-ribbon Actuators

“…Results suggest that both insulator and medium permittivity should be high, with insulator permittivity being the greater of the two. Carbon nanotube actuator 1 [23] Piezoelectric material 1.7 [4] Electric liquid-crystal elastomer 4 [24] Electrostrictive material 4.3 [4] Shape memory alloy 5 [4] Peano-HASEL 10 [25] Electroactive gel 18 [26] McKibben pneumatic actuator 30 [27] Biological muscle 40 [4] Pleated pneumatic artificial muscles 42 [28] Thermal liquid-crystal elastomer 45 [29] Vacuum-actuated muscle-inspired pneumatic structures 45 [30] Multilayer stacked dielectric elastomer actuator 46 [12] Coiled polymer actuator 49 [5] Traditional pneumatic, hydraulic and linear electromagnetic actuators 50 [4], [31] High-displacement textile pneumatic artificial muscle 65 [8] Shape memory polymer 77 a [1] Single layer dielectric elastomer actuator 79 [11] Fluid-driven origami-inspired artificial muscles 90 [9] Shape-memory alloy coil 92 [2] Spiral coiled polymer 98.85 [3] Origami-based vacuum pneumatic artificial muscle 99.7 [10] Electro-ribbon actuator 99.84 [13] a. Shape-memory polymers stretched seven times their original length showed up to 90 % strain recovery rate implying contractile strains of 77 %…”

3D in vitro models of skeletal muscle: myopshere, myobundle and bioprinted muscle construct

“…With the microextrusion method, the techniques typically used for the dispersion of the biomaterials onto a substrate are pneumatic-, piston-and screw-dispensers [123]. Construction of large free-form tissue structures appeared to be quite difficult due to inadequate mechanical stability and printability [124]. The laser-assisted method has the advantage to be nozzle-free, which can avoid clogging observed with the previous methods, but is limited by the requirement of a rapid hydrogel gelation to achieve high-resolution printed patterns, resulting in low flow rates [125].…”

3D Graphene Scaffolds for Skeletal Muscle Regeneration: Future Perspectives

“…3D printing has been employed to create artificial muscles that can be moved thanks to the photothermal properties of graphene that can be embedded in prosthesis and allow performing complex motions driven by laser light stimulation (Peele et al, 2015;Han et al, 2019;Helps et al, 2019;Zhou et al, 2019).…”