High Precision Microfluidic Devices for High Power Laser Experiments

The micro target fabrication scientists at the Central Laser Facility, part of STFC-UKRI, develop micro targets for high power laser experiments. The next generation of lasers have increased repetition rates (up to 10Hz) making high repetition targetry an important research avenue. The researchers rely on microfluidic devices to crease liquid sheet targets of sub micron for  high-power laser experiments. Relying on machining or etching for fabricating microfluidic channels is costly and time consuming. The team was looking for a new solution to rapidly prototype new target design geometries for their experiments.

Developing the Targets

The team is looking to create a liquid target using micro channels to create a leaf as the liquid flows from the channels. The channel design directly affects the quality of the leaf, which is judged by the leaf’s width and thickness. The goal is for the leaf to have a width of a few mm and a thickness of a few 100 nm.

Liquid leaf target created as the liquid flows from the channels

The channel design is extremely important for the experiments as the behavior of the liquid changes depending on the channel. The channel needs to be smooth to reduce turbulence and the shape of the exit is extremely important as it has a massive impact on the final leaf.

Using High Precision 3D Printing to Prototype the Channels

To create the liquid sheet, the team printed a 20mm x 15mm x 5mm block with a 30µm deep channel and a 100µm outlet. The overall part size is relatively large compared to the small, precise channel.  Using their microArch S240, the team was able to print the larger part while maintaining the precision and accuracy required for the channel.

The current channels that are used are made of tungsten as they can be accurately machined. In this instance the team used high precision 3D printing with their microArch printer to quickly and accurately design the channels providing an affordable option for research and for rapid prototyping.

Original tungsten part
Part fabricated with high precision 3D printing

As the team continues to develop targets for their high power laser experiments, they will be able to continue using their microArch S240 to iterate quickly on new channel designs. For more information about the microArch S240 and PµSL technology, contact BMF.