TY  - EJOU
AU  - Ni, Ke 
AU  - Wang, Zhengzhi 

TI  - Magnetic	Micropillar	Structures	for	Programmable	and Reprogrammable	 Actuation
T2  - The International Conference on Computational \& Experimental Engineering and Sciences

PY  - 2023
VL  - 25
IS  - 4
SN  - 1933-2815

AB  - Stimuli-responsive	 micropillar	 structures	 that	 can	 perform	 dynamics	 and	 reversible	 deformations	
according	to	external	stimuli	have	been	applied	in	a	wide	spectrum	of	fields,	including	object	manipulation,	
soft	miniature	robots,	and	 functional	surfaces.	However,	it	remains	a	challenge	 to	exhibit	programmable	
actuation	 behaviors	 for	 applications	 that	 require	 on-demand	 deformation	 response.	 Herein,	 a	 two-step	
photomask-assisted	 template	 casting	 technique	 is	 developed	 to	 fabricate	 a	 hybrid	 magnetic	 micropillar	
array	 for	 programmable	actuation.	By	modulating	 the	 spatial	 distribution	 of	 the	magnetic	 nanoparticles	
within	 the	 elastomer	 micropillars,	 the	 bending	 deformations	 of	 the	 micropillars	 with	 different	 particle	
distributions	can	vary	near	one	order	of	magnitude	under	the	same	magnetic	field.	Through	the	two-step	
technique,	the	micropillars	with	different	deformation	responses	can	be	arranged	into	any	desired	spatial	
pattern	 for	 various	 exciting	 novel	 applications,	 as	 demonstrated	 in	 encryptable	 surface	 and	 trackprogrammable	 micro-target	 transportation.	 Furthermore,	 to	 overcome	 the	 limitation	 that	 the	 bent	
deformation	of	the	micropillars	is	fixed	once	the	fabrication	is	completed,	a	concept	for	core-shell	magnetic	
micropillars,	which	can	achieve	not	only	programmable	but	also	reprogrammable	actuation	in	response	to	
external	magnetic	stimuli.	The	micropillars	are	composed	of	elastomeric	hollow	shells	encapsulating	liquid	
magnetic	nanocomposite	resin.	The	spatial	distribution	of	the	magnetic	nanoparticles	inside	the	liquid	resin	
core	can	be	dynamically	modulated	within	one	single	micropillar	to	regulate	the	actuation	configuration	of	
the	pillar.	In	this	way,	the	spatial	pattern	of	the	micropillars	with	contrast	bending	configurations	can	be	
dynamically	and	repeatedly	configured	through	a	local	magnetic	field	for	writing	and	a	global	magnetic	field	
for	erasing,	which	can	be	applied	in	the	applications	of	rewritable	paper	and	recyclable	displays.	The	hybrid	
and	core-shell	magnetic micropillars	reported	here	provide	versatile	prototypes	and	inspirations	 for	 the	
programmable	and	reprogrammable	stimuli-responsive	microstructures.
KW  - Stimuli-responsive	microstructures;	magnetic	micropillars;	programmable;	reprogrammable

DO  - 10.32604/icces.2023.09248