PNIPAM基异质双层水凝胶智能结构4D打印和多曲率变形

4D Printing and Multi-curvature Deformation of PNIPAM-based Heterogeneous Bilayer Hydrogel Intelligent Structure

聚(N-异丙基丙烯酰胺)(PNIPAM)水凝胶在生物医疗、软体机器人等领域有着广泛的应用。为了实现多曲率变形,提出一种具有异质被动层的PNIPAM基水凝胶智能结构。该智能结构由均质主动层与异质被动层组成,其中异质被动层由多种具有不同弹性模量的材料组成。基于该智能结构开发了利用墨水直写打印工艺的多材料4D打印一体化制造方法,阐述了多曲率变形基本原理和制造工艺流程,制备了适用于该工艺的4D打印墨水,优化了喷头移动速度、背压等工艺参数对线宽及周期的影响,制造了异质被动层由两种不同弹性模量材料组成的PNIPAM基水凝胶智能结构的典型案例,并验证了该结构能实现多曲率变形。

Poly(N-isopropylacrylamide)(PNIPAM)hydrogel was widely used in biomedical,soft robot and other fields.In order to achieve multi-curvature deformation,a PNIPAM based hydrogel intelligent structure with heterogeneous passive layer was proposed.The smart structure was composed of homogeneous active layer and heterogeneous passive layer,in which the heterogeneous passive layer was composed of a variety of materials with different elastic modulus.Based on the intelligent structure,a multi-material four dimensional(4D)printing integrated manufacturing process using direct ink writing printing process was developed.The basic principle and manufacturing process of multi-curvature deformation were described,and 4D printing ink suitable for this process was prepared.The influences of nozzle moving speed and back pressure on line width and period were optimized.A typical case of PNIPAM based hydrogel smart structure consisting of two different elastic modulus materials was fabricated.The results demonstrate that the smart structure of PNIPAM based hydrogel with heterogeneous passive layer could cause multi-curvature deformation.