3D printed lab-on-a-chip device is first to achieve true microfluidic flow

Researchers in the engineering and chemistry departments of Brigham Young University in Utah claim that the 3D-printed device represents the first use of the technique to produce channels at a scale of much less than 100µm, narrow enough to produce the microfluidic flow effects needed for lab-on-a-chip operations. The team claims that its method is faster than current microfluidic manufacturing techniques, and also does not require cleanroom conditions.

Previous attempts at printing microfluidic devices have not been able to achieve channels narrow enough for surface tension to provide enough force to pull the fluid in the device through the channels. "So we decided to make our own 3D printer and research a resin that could do it," said electrical engineering professor Greg Nordin.

Working with chemistry professor Adam Woolley, Nordin built a 3D printer that works by a technique known as digital light processing stereolithography (DLP-SLA). This uses a micromirror array chip — a device used in most consumer projectors — to project a pattern for each layer of the printed object onto a light-sensitive resin. Most such printers contain an LED to project light at a wavelength of 405nm, but the BYU team instead used a 385nm LED, which dramatically increases the available selection of UV absorbers for resin formulation.