Fabrication of 3D Micro-Blades for the Cutting of Biological Structures in a Microfluidic Guillotine

Abstract

Micro-blade design is an important factor in the cutting of single cells and other biological structures. This paper describes the fabrication process of three-dimensional (3D) micro-blades for the cutting of single cells in a microfluidic “guillotine” intended for fundamental wound repair and regeneration studies. Our microfluidic guillotine consists of a fixed 3D micro-blade centered in a microchannel to bisect cells flowing through. We show that the Nanoscribe two-photon polymerization direct laser writing system is capable of fabricating complex 3D micro-blade geometries. However, structures made of the Nanoscribe IP-S resin have low adhesion to silicon, and they tend to peel off from the substrate after at most two times of replica molding in poly(dimethylsiloxane) (PDMS). Our work demonstrates that the use of a secondary mold replicates Nanoscribe-printed features faithfully for at least 10 iterations. Finally, we show that complex micro-blade features can generate different degrees of cell wounding and cell survival rates compared with simple blades possessing a vertical cutting edge fabricated with conventional 2.5D photolithography. Our work lays the foundation for future applications in single cell analyses, wound repair and regeneration studies, as well as investigations of the physics of cutting and the interaction between the micro-blade and biological structures.

Direct laser writing-enabled 3D printing strategies for microfluidic applications

“…2f). [124][125][126] Researchers have harnessed this geometric control to produce master moulds that support studies in the life sciences, such as to resolve tapered semi-cylindrical trapping channels for plant parasitic nematodes (Fig. 2g) 127 as well as microfluidic devices with topographical features (e.g., pyramid arrays) for investigations of cell physicobiology (Fig.…”

Preparation, Stimulus–Response Mechanisms and Applications of Micro/Nanorobots

“…In terms of scalability, more stress design preparation methods for more material systems need to be investigated to meet different application requirements. At the micro-and nanoscale, 3D direct laser writing (DLW) allows the precise batch preparation of complex polymer structures with high resolution [161][162][163]. Typically, we use DLW techniques to fabricate helically structured micromotors (Figure 6A) [9,20,31,65].…”

Microfluidic Surgery in Single Cells and Multicellular Systems

“…In these two studies, the blade had a vertical cutting edge since it was fabricated by conventional 2.5-dimensional (2.5D) photolithography. High resolution 3D-printing methods, such as those employing two-photon polymerization, could enable the fabrication of blades with complex 3D geometries with improved cutting performance …”

“…High resolution 3D-printing methods, such as those employing two-photon polymerization, could enable the fabrication of blades with complex 3D geometries with improved cutting performance. 171 Instead of a physical blade, it is also possible to bisect single cells using hydrodynamic forces. The hydrodynamic cell splitter contained a microfluidic cross-junction that used extensional flow to stretch Stentor coeruleus until the cell split into two.…”