Project Details
Projekt
Switchable, bistable microactuator systems based on stimuli-responsive polymers
Subject Area
Microsystems
Synthesis and Properties of Functional Materials
Synthesis and Properties of Functional Materials
Term
since 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 424614922
Stimuli-responsive hydrogels are compelling materials for generating microactuator systems within microfluidic devices due to their 3D printability, tunable features, and ability to interact harmlessly with cells. Current hydrogel-based microactuators, however, tend to be very simple, and complex features, e.g. bistability, remain largely unexploited; therefore, the field remains immature and many potential applications have not yet been realized. To build on work from the first funding period, where we have thoroughly characterized and improved the actuation of PNIPAM-based thermoresponsive microactuators, we herein propose a novel strategy to achieve bistable microactuator systems based on combinations of thermoresponsive/pH responsive hydrogels and shape-memory polymers. The materials will be shaped into microactuator systems using two-photon direct laser writing, which allows for the fabrication of highly complex 3D geometries, and their actuation in response stimuli will be characterized in-depth and optimized. We will explore the advantages and disadvantages of using thermally responsive hydrogels to construct microactuator arrays/systems by analyzing the cross-talk that occurs between individual microactuators. We hypothesize that the combination of a shape-memory material with a thermoresponsive and/or pH-responsive material can be used to take even advantage of cross-talk between individual microactuators to increase the functionality of the whole microactuator system. The final demonstration of this proposed project will consist of a system of microactuators in different shapes and configurations, including active microchannel walls and stimuli responsive microvalves for applications in dynamic microfluidic systems. While commercially available state-of-the-art microfluidic devices suffer from having their properties pre-defined during fabrication, our microactuator system will instead be based on active features that will add dynamic flexibility into microfluidic devices through the cooperation of individual microactuators. Similar principles will be used to design autonomously operating cell and organoid culturing systems, where pH-responsive microvalves will regulate cell medium flow. The success of this project will result in unprecedented adaptability and autonomy in microfluidic systems, leading to improved accessibility and throughput of a wide variety of tools and procedures.
DFG Programme
Priority Programmes
