A Rewritable, Reprogrammable, Dual Light‐Responsive Polymer Actuator

Abstract

We report on the fabrication of a rewritable and reprogrammable dual‐photoresponsive liquid crystalline‐based actuator containing an azomerocyanine dye that can be locally converted into the hydroxyazopyridinium form by acid treatment. Each dye absorbs at a different wavelength giving access to programmable actuators, the folding of which can be controlled by using different colors of light. The acidic patterning is reversible and allows the erasing and rewriting of patterns in the polymer film, giving access to reusable, adjustable soft actuators.

Selective Decrosslinking in Liquid Crystal Polymer Actuators for Optical Reconfiguration of Origami and Light‐Fueled Locomotion

“…Herein, we demonstrate an ew approach for optical reconfiguration of as ingle LCN actuator,n ot only for changing its shape transformation as in the previous studies, [8][9][10] but also for changing locomotion behavior,w hich is unprecedented. Thep rocess is based on controlled photodecrosslinking,w hich requires only the use of light at one wavelength, conducted at room temperature and involves no mechanical deformation or reshaping of the polymer.W e show that through optical reconfiguration, the LCN can be used to prepare origamizers which, in contrast with conventional origami polymers,c an fold and unfold under stimulation to switch between ap lanar sheet and various targeted three-dimensional (3D) shapes.M ost interestingly,u sing ad ye-doped LCN actuator,alight-fueled microwalker was optically reconfigured to reverse its locomotion direction with respect to laser scanning.T his first-time achievement is as ignificant step forward in optical reconfiguration of LCN actuator functions.…”

“…Thec hallenge of reconfiguring as ingle LCN actuator to achieve on-demand shape changes has been addressed in af ew recent studies.O no ne hand, ap H-rewritable LCN actuator was demonstrated using ap olymer containing pHresponsive azomerocyanine that can be reversibly converted into hydroxyazopyridinium. [8] Since the two molecular species absorb light of different wavelengths,b yp atterning their distribution in the LCN through pH change,various actuation behaviors can be activated by light at wavelengths that excite one of the chromophores.O nt he other hand, as ingle LCN containing exchangeable epoxy acid bonds for crosslinking and doped with carbon nanotubes was shown to allow nearinfrared (NIR) light-assisted reshaping for the actuator reconfiguration. [9] Upon irradiation, the local temperature of the vitrimer can rise to activate the transesterification, making it possible to mechanically deform the irradiated areas and thus alter the LC orientation in the actuator.More recently,anoptical reconfiguration method was proposed for an LCN actuator bearing azobenzene mesogens and containing adye.…”

Photomobile Polymer Materials with Complex 3D Deformation, Continuous Motions, Self‐Regulation, and Enhanced Processability

“…e) Photoinduced deformation of a CLCP film containing a pH‐sensitive photochromic azo dye. Reproduced with permission . Copyright 2017, Wiley‐VCH.…”

Reconfigurable and programmable origami dielectric elastomer actuators with 3D shape morphing and emissive architectures

“…For instance, modular self-reconfigurable robots can change their shapes by rearranging individual modules to adapt to different circumstances and tasks 2 . Liquid crystal polymer networks that respond to light or humidity stimuli can be reconfigured for different shape morphing by acidic patterning 3 , base treatment 4 , or photochemical programming 5 . Among the varieties of soft actuators, the dielectric elastomer actuator (DEA) has been intensively investigated, with the benefits of scalable dimensions, simple architectures, excellent mechanical compliance, and large deformations [6][7][8][9] , making it an ideal candidate for programmable soft robotic systems.…”