Shape-switching microrobots for medical applications: the influence of shape in drug delivery and locomotion.
The effect of dynamic shape switching of hydrogel bilayers on the performance of self-folding microrobots is investigated for navigation in body orifices and drug release on demand. Tubular microrobots are fabricated by coupling a thermoresponsive hydrogel nanocomposite with a poly(ethylene glycol)diacrylate (PEGDA) layer, to achieve spontaneous and reversible folding from a planar rectangular structure. Graphene oxide (GO) or silica-coated superparamagnetic iron oxide nanoparticles are dispersed in the thermoresponsive hydrogel matrix to provide near-infrared (NIR) light sensitivity or magnetic actuation, respectively. The NIR light-responsive microstructures are fabricated for triggered drug delivery while magnetic nanocomposite-based microrobots are used to analyze the role of shape in locomotion. Experimental analysis and computational simulations of tubular structures show that drug release and motility can be optimized through controlled shape change. These concepts are finally applied to helical microrobots to show a possible way to achieve autonomous behavior.
†Institute of Robotics and Intelligent Systems, ETH Zürich, Tannenstrasse 3, 8092 Zurich, Switzerland.
Stefano
S
Fusco
†Institute of Robotics and Intelligent Systems, ETH Zürich, Tannenstrasse 3, 8092 Zurich, Switzerland.
Hen-Wei
HW
Huang
†Institute of Robotics and Intelligent Systems, ETH Zürich, Tannenstrasse 3, 8092 Zurich, Switzerland.|#Faculty of Life Sciences, University of Manchester, Michael Smith Building, Manchester, M13 9PT, United Kingdom.
Kathrin E
KE
Peyer
‡Micro and Nanosystem Group, ETH Zürich, Tannenstrasse 3, 8092 Zurich, Switzerland.
Christian
C
Peters
†Institute of Robotics and Intelligent Systems, ETH Zürich, Tannenstrasse 3, 8092 Zurich, Switzerland.
Moritz
M
Häberli
†Institute of Robotics and Intelligent Systems, ETH Zürich, Tannenstrasse 3, 8092 Zurich, Switzerland.
André
A
Ulbers
§Particle Technology Laboratory, ETH Zürich, Sonneggstrasse 3, 8092 Zurich, Switzerland.
Anastasia
A
Spyrogianni
∥Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain.
Eva
E
Pellicer
⊥Institució Catalana de Recerca i Estudis Avançats (ICREA) and Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain.
Jordi
J
Sort
§Particle Technology Laboratory, ETH Zürich, Sonneggstrasse 3, 8092 Zurich, Switzerland.
Sotiris E
SE
Pratsinis
†Institute of Robotics and Intelligent Systems, ETH Zürich, Tannenstrasse 3, 8092 Zurich, Switzerland.
Bradley J
BJ
Nelson
†Institute of Robotics and Intelligent Systems, ETH Zürich, Tannenstrasse 3, 8092 Zurich, Switzerland.
Mahmut Selman
MS
Sakar
†Institute of Robotics and Intelligent Systems, ETH Zürich, Tannenstrasse 3, 8092 Zurich, Switzerland.
Salvador
S
Pané
D016503:Drug Delivery Systems / Q000295:instrumentation*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D008027:Light; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*; D013696:Temperature
C437167:poly(ethylene glycol)diacrylate; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols
drug delivery; hydrogel nanocomposites; magnetic manipulation; microrobotics; self-folding bilayers