Scanning two-photon continuous flow lithography for the fabrication of multi-functional microparticles

Abstract

In this work, we demonstrate the high-throughput fabrication of 3D microparticles using a scanning two-photon continuous flow lithography (STP-CFL) technique in which microparticles are shaped by scanning the laser beam at the interface of laminar co-flows. The results demonstrate the ability of STP-CFL to manufacture high-resolution complex geometries of cell carriers that possess distinct regions with different functionalities. A new approach is presented for printing out-of-plane features on the microparticles. The approach eliminates the use of axial scanning stages, which are not favorable since they induce fluctuations in the flowing polymer media and their scanning speed is slower than the speed of galvanometer mirror scanners.

Ink Formulation and Selection for Biological Applications of Two-Photon Polymerization

“…Some applications of TPP in the form of (a) multifunctional microparticles as self-aligning cell carriers (Reproduced with permission from ref Copyright 2020 The Optical Society), (b) microneedle arrays for transdermal delivery, microneedle arrays for transdermal delivery (i) with molding (adapted from Figure 3 in ref (published under the Creative Commons Attribution 4.0 International License)) and (ii) without molding (Reproduced with permission from ref . Copyright 2007 John Wiley and Sons), (c) pentamode mechanical metamaterials as biomedical devices (Reproduced with permission from ref .…”

Flow lithography for structured microparticles: fundamentals, methods and applications

“…Recently, multi-material particles were also demonstrated. 142 In summary, the simplest 1D particles can be produced at a throughput of up to 10 6 particles per minute, whereas some of the more sophisticated 3D particles can only be produced at a rate of few particles per minute, e.g., using VFL and SML techniques (Fig. 22).…”

“…The microparticles are cured point-by-point in a continuous flow by synchronizing the laser scanning with the downstream velocity of the particle as it is manufactured. 142 The laser beam was precisely scanned with respect to the microchannel using a synchronized piezo-stage, galvanometer and an opto-acoustic switch for fabricating arbitrary 3D shapes with submicron-sized features. A fabrication rate of up to 30 particles per second was reported.…”

“…A fabrication rate of up to 30 particles per second was reported. 142 Different 3D particle shapes such as gears, dumbbell cell carriers, helical coils, etc. were fabricated using TPL (Fig.…”

Microfluidic Preparation of Janus Microparticles With Temperature and pH Triggered Degradation Properties

“…The fluid in the microfluidic chip is exposed to an ultraviolet beam with preset shape, causing the irradiated fluid to partially polymerize according to the beam shape to obtain Janus particles. The whole preparation process can be completed with the help of a commercial fluorescence microscope ( Chizari et al, 2020 ; Sun et al, 2014 ). Microfluidic method can endow Janus particles with complex structure (such as three-dimensional asymmetric structure) or sophisticated morphology (such as graphic coding morphology) and the control of particle size, which greatly expands the design and application scope of Janus particles ( Shepherd et al, 2006 ).…”