Rapid prototyping of PDMS microchannels for animal and plant cells using cutting plotter and double casting

Abstract

The facilitation of access to rapid and low-cost microfabrication methods is essential for improving the development cycles of testing new chip designs and research ideas. A simple fabrication method of biocompatible microchannels with a height of 0.3 mm is significant for biological scientists to study animal and plant cells (∼0.1 mm). Microfabrication using a cutting plotter and a knife blade provides a rapid and low-cost technology. In a previous study, designed cut pieces were used as a channel mold, but they were easy to deform during handling, and therefore the large-scale production of channels was difficult. Moreover, it is required to characterize the cutting process of 0.3-mm-thick sheets with a low-cost plotter. Here, we report the development of an easy fabrication method of 0.3-mm-high polydimethylsiloxane (PDMS) microchannels based on a desktop cutting plotter (300 USD) and an engraved sheet as follows. 1) A 0.3-mm thick sheet of cast-coated paper or silicone rubber was used as a mold material and patterns were created with a cutting plotter. 2) It was pasted to a double-sided tape to make a master mold of a flow channel. 3) The mold was replicated in PDMS to make a negative mold. 4) This PDMS mold was again transferred to a final PDMS chip. 5) It was bonded to a glass substrate to form a PDMS flow channel. We characterized the pattern transition of rectangular shapes from an engraved sheet mold to a final PDMS channel, that is essential for the design of a channel using this method. I- and Y-shaped microchannels (height: 0.3 mm) were fabricated and fluorescent particles and 0.2-mm diameter Volvox were introduced into the channels to show their performances.