Fabrication of Perforated PDMS Microchannel by Successive Laser Pyrolysis

Abstract

Poly(dimethylsiloxane) has attracted much attention in soft lithography and has also been preferred as a platform for a photochemical reaction, thanks to its outstanding characteristics including ease of use, nontoxicity, and high optical transmittance. However, the low stiffness of PDMS, an obvious advantage for soft lithography, is often treated as an obstacle in conducting precise handling or maintaining its structural integrity. For these reasons, a Glass-PDMS-Glass structure has emerged as a straightforward alternative. Nevertheless, several challenges are remaining in fabricating Glass-PDMS-Glass structure through the conventional PDMS patterning techniques such as photolithography and etching processes for master mold. The complicated techniques are not suitable for frequent design modifications in research-oriented fields, and fabrication of perforated PDMS is hard to achieve using mold replication. Herein, we utilize the successive laser pyrolysis technique to pattern thin-film PDMS for microfluidic applications. The direct use of thin film at the glass surface prevents the difficulties of thin-film handling. Through the precise control of photothermal pyrolysis phenomena, we provide a facile fabrication process for perforated PDMS microchannels. In the final demonstration, the laminar flow has been successfully created owing to the smooth surface profile. We envision further applications using rapid prototyping of the perforated PDMS microchannel.

Bioderived Laser-Induced Graphene for Sensors and Supercapacitors

“…Also, other noncarbonaceous substrates for laser patterning have been reported in literature, such as poly-(dimethylsiloxane) (PDMS). 36,37 A detailed description of the photochemical and photophysical conversion mechanisms of bioderived precursors into LIG is provided in a recent review, together with an insight on the role of interfaces in the synthesis. 38 Almost all bioderived precursors tested so far for LIG production are lignocellulosic materials such as wood or some processed part of it (cork, paper, lignin, and nanocellulose), as highlighted in Figure 2a.…”

“…A hybrid two-step process has also been proposed, with an initial traditional pyrolysis of the precursor to amorphous carbon, followed by a conversion into LIG by laser-induced pyrolysis. − This type of LIG is not considered in this review because the focus is on the direct conversion of the bioderived precursors through just laser scribing. Also, other noncarbonaceous substrates for laser patterning have been reported in literature, such as poly­(dimethylsiloxane) (PDMS). , …”

Fabrication of Polymer Microfluidics: An Overview

“…In addition, increasing the beam size and the number of repeated scanning increased the depth of the microchannels, where PGS increased the most among the three polymers. Min et al performed successive laser pyrolysis on PDMS, which was coated on the glass substrate in advance [ 100 ]. The pyrolyzed SiC was detached from the glass substrate to create a PDMS microchannel.…”

Rapid Printing of High-Temperature Polymer-Derived Ceramic Composite Thin-Film Thermistor with Laser Pyrolysis

“…Moreover, a laser can be faster and more conveniently applicable to various substrates than a furnace, − which can help optimize conventional methods. Laser pyrolysis of organic polymers (polysilazane/polydimethylsiloxane) has been applied to fabricate multiple ceramic coatings, , sophisticated polydimethylsiloxane microstructures, − and flexible sensors. − Laser reductive sintering has been demonstrated to fabricate highly sensitive temperature sensors . Thus, laser techniques have great potential for fabricating PDC high-temperature functional films, but there are few related kinds of research.…”