2024/04/15 by Chantal Barwig, Annabelle Sonn, Tobias Spratte +4 · 1 voice · 2 citations
Engineering · #3D Printing in Biomedical Research #Electrohydrodynamics and Fluid Dynamics #Innovative Microfluidic and Catalytic Techniques Innovation
paper · pdf · doi:10.1002/aisy.202300829
openalex publication_date 2024/04/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Microfluidic tools enable to investigate and manipulate various chemical and biological processes at small scales. As a result, it finds widespread applications in lab‐on‐chip devices, drug delivery systems, or miniaturized cell cultures. However, microfluidic devices are still limited in their flexibility and are often designed to fulfill a single functionality. Moreover, technologies to introduce dynamic functionalities with high precision and at high resolution after the development of a continuous phase microfluidic chip remain scarce. Herein, two‐photon polymerization direct laser writing is introduced as a suitable approach to equip continuous phase microfluidic chips with structurally defined thermoresponsive poly( N‐ isopropyl‐acrylamide) (pNIPAM) microactuators. Harnessing the lower critical phase transition temperature of pNIPAM, and upon controlling specific design parameters, the efficient catch and release of polystyrene beads of different sizes using a pNIPAM micropillar brush array is demonstrated. Moreover, a biocompatible pNIPAM microgripper array is designed to subsequently capture and release differently sized (single) cell populations. Overall, the method offers great flexibility and a high degree of freedom toward the fabrication of dynamic microfluidic devices with great adaptability to experimental conditions in real time.