3D Printed Electrodes Make Microfluidic Devices Cheaper and Quicker to Fabricate

Researchers at Imperial College London wanted to develop a microfluidic biosensor for analysis of cancer cells that was quicker and easier to produce. A microfluidic device involves biological material traveling through tiny channels and electrodes passing electrical current through the material so that a microchip can analyze what the material contains. The Imperial College London scientists focused on the electrode in improving their device – by 3D printing the electrode, they could save a lot of time and money, they discovered.

Dr. Ali Salehi-Reyhani

“We had an idea about how we could pattern these electrodes in a simple manner,” said Imperial College London chemistry department lead researcher Dr. Ali Salehi-Reyhani. “And it is using the patterns of microfluidic channels to pattern that down onto a surface, so you can get these complicated designs that would otherwise be extremely difficult to make.”

The electrode sits between the channels of the microfluidic device, and the biological material flows over it. Dr. Salehi-Reyhani and his team realized that they could design an electrode on a computer and 3D print it.

“We draw something on the PC [personal computer], five minutes later you have your template and half an hour after that you have your got electrodes,” said Dr. Salehi-Reyhani.

They had a little fun with the technology while testing it out, as well.

“We like IronMan so we did a Google image search and loaded it into Photoshop and printed it out,” Dr. Salehi-Reyhani continued.

Conventional labs on a chip use gold electrodes, and while the 3D printed material was not as conductive as gold, it was still conductive enough to get the job done, especially after some improvements made by the researchers.

“All you need was to send an alternating current, alternating voltage to disrupt the cells,” said Dr. Salehi-Reyhani.

Dr. Salehi-Reyhani hopes that the 3D printing of things like electrodes will democratize the creation of highly specialized scientific equipment like microfluidic devices. He believes that the scientific community can benefit from the input of the maker and hacker community, with its inclination towards coming up with cheaper and quicker ways to create things, even for fields like science and health care.

“With our method researchers and startups can more easily design and develop analytical devices, even when they need electronics that can’t be bought off-the-shelf,” he said. “Community hackspaces are great for democratising science, allowing more people to try out new technology solutions. We hope this method will allow bioelectronics to benefit from that ecosystem of hackers getting hands-on with problems and solutions in healthcare.”

The researchers had to make sure that the 3D printed electrode material was compatible with the biomolecules for the bioassay analysis, and they also needed to ensure that the electrode would stick to the substrate upon which the lab on a chip sits. The next step is to produce a microfluidic biosensor that can undergo clinical trials in medical centers for use by non-experts. The biosensor could detect the difference between viral and bacterial infections with just a drop of a patient’s blood. Dr. Salehi-Reyhani also wants to look into developing wearable biosensor applications like sweat analysis.

The research is documented in a paper entitled “Micropatterning of planar metal electrodes by vacuum filling microfluidic channel geometries.” Authors of the paper include Stelios Chatzimichail, Pashini Supramanian, Oscar Ces and Ali Salehi-Reyhani.

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