3D Printed Acoustically Programmable Soft Microactuators

Abstract

The concept of creating all-mechanical soft microrobotic systems has great potential to address outstanding challenges in biomedical applications, and introduce more sustainable and multifunctional products. To this end, magnetic fields and light have been extensively studied as potential energy sources. On the other hand, coupling the response of materials to pressure waves has been overlooked despite the abundant use of acoustics in nature and engineering solutions. In this study, we show that programmed commands can be contained on 3D nanoprinted polymer systems with the introduction of selectively excited air bubbles and rationally designed compliant mechanisms. A repertoire of micromechanical systems is engineered using experimentally validated computational models that consider the effects of primary and secondary pressure fields on entrapped air bubbles and the surrounding fluid. Coupling the dynamics of bubble oscillators reveals rich acoustofluidic interactions that can be programmed in space and time. We prescribe kinematics by harnessing the forces generated through these interactions to deform structural elements, which can be remotely reconfigured on demand with the incorporation of mechanical switches. These basic actuation and analog control modules will serve as the building blocks for the development of a novel class of micromechanical systems powered and programmed by acoustic signals.

Sustainable Robots 4D Printing

“…In this respect, Kaynak et al [ 83 ] presented a new approach to creating micromechanical soft actuators using acoustic signals as a power source. The researchers made tiny capsules with air bubbles inside them using 3D printing ( Figure a).…”

“…[238] Unfortunately, because of their restricted range of mechanical and chemical characteristics, these polymers are only suitable for particular kinds of tissue replacement scaffolds. TPETA, [83] GelMA, [84,85] Acrylamide (AAm), [117] PEGDA, [88][89][90][91]107,113,117,130,140,147] photocrosslinkable polycaprolactone dimethyl acrylate (PCLDMA), [87,103] photocurable PLA, [110] photocurable polycaprolactone diacrylate (PCLDA), [86,129] gelatin, [99] photocurable chitosan-based polymer, [34] pentaerythritol tetraacrylate (PETA), [107] photocurable alginate-based polymer, [100] poly(ethylene glycol) methyl ether methacrylate (PEGMA), [101] propylene glycol methyl ether acetate (PGMEA), [108] PEGgel, [92] and polyethylene glycol dimethacrylate (PEGDMA) [149] are among biodegradable materials used to make appropriate photocurable polymer for VPP technique. In the following sections, several facets of each VPP approach have been addressed in more detail.…”

“…Regarding their applicability, biodegradable 3D/4D printed soft actuators are utilized in many fields, such as agriculture, [ 60 ] biomedicine, [ 61–93 ] micro positioning, [ 67,79,94–97 ] smart surgical instruments, [ 64,98–101 ] soft rehabilitation devices, [ 98,102,103 ] drug delivery microswimmers, [ 64,67,68,70,72,73,77,84,85,88,94,34,104–108 ] sustainable electronics devices, [ 109–111 ] soft smart fabrics, [ 64 ] muscle tissue membranes, [ 65,76,89,94,96,112,113 ] in‐vivo robotics, [ 67,74,83,86,89–91,93,99–101 ] wearable devices, [ 95,103,111,114–118 ] soft smart prosthetics, [ 114 ] bionic devices, [ 69,72,73,114 ] aeronautics, [ 119,120 ] health monitoring equipment, [ 111,118 ] edible robots, [ 121 ] biomimetic scaffolds, [ 30,62,76,97,115,122,123 ] environmental monitoring equipment, […”

“…Reproduced with permission. [ 83 ] Copyright 2023, Mary Ann Liebert, Inc. 3D‐printed biodegradable chipless sensor for wireless subsoil health monitoring. Reproduced under the term of CC‐BY license [ 137 ] Copyright 2022, The Authors, published by Springer Nature.…”

Bistable, Pneumatically Actuated Microgripper Fabricated Using Two‐Photon Polymerization and Oxygen Plasma Etching

“…A bistable mechanism's ability to occupy different discrete positions without constant power input is desirable in many applications, such as in switches, relays, [ 21 ] or nonexplosive release mechanisms. [ 22 ] Bistable mechanisms have already been explored at the microscale, with classical MEMS fabrication method for open loop actuator [ 23 ] but also more recently using 2PP with in‐plane mechanism actuated by acoustic‐flow‐induced force [ 24 ] or microscale logic gates actuated using optical tweezers. [ 25 ] Bistable mechanisms have also been used in macroscale pneumatic actuators for soft robotics.…”