Using additive manufacturing to develop diagnostics

Paul Marshall, CEO and co-founder of Rapid Fluidics, explains how the company uses 3D printing for microfluidics and diagnostics development.

The development of diagnostic systems has understandably seen a huge rise in recent years: 

• The average man on the street now knows the term “PCR”, even if they don’t know what it means. 
• They know that lab testing can give better results than a point of need test but is less convenient and more expensive. 
• They are also coming round to the idea that lab quality tests don’t need to be carried out in a lab but can be carried out at the point of need at a lower cost. 

This is driving a need to develop high quality, inexpensive, easy-use single use diagnostics. As these devices get smaller to reach that point of need, they need to incorporate microfluidics. Rapid Fluidics has a technique to produce fully functional microfluidic prototypes in a matter of hours, rather than weeks. Following a PhD at Newcastle University, we have developed a method of relatively inexpensive 3D-printing microfluidic prototypes, offering a 24-hour turnaround of bespoke designs. This allows customers to try multiple iterations of early-stage designs in a very short space of time, reducing the time and cost of product development.

There are various traditional methods for producing and sealing microfluidics such as CNC machining; hot embossing; and injection moulding. These all require secondary bonding such as adhesives; solvent diffusion bonding; laser and ultrasonic welding.

Rapid Fluidics focuses on 3D-printed microfluidics. We can produce open channels very simply using our high-resolution printers, which could be enclosed through any of the conventional methods listed. But we can avoid the time, expense, and risk of all those techniques by simply 3D-printing a lid directly on to the microfluidic layer. This has many advantages: the key one being time, but also the lid itself can include additional features such as more channels with vias linking the layers. External connectors can simply be incorporated, from mounting features for manifolds, barbed tube fittings or threaded holes.

The microfluidic market has only been around for a few decades and is small but there are several companies around the world providing prototyping and production services, each with their own processing niche. While they all have their respective strengths, Rapid Fluidics offers a short turnaround. We use modified commercially available 3D printers with lower overheads to cover. Representatives from the industry agree that offering prototyping as an outsourced service is a growth industry, de-risking product development for our clients. From our market research, 95% of our customer base are SMEs favouring low-CAPEX outsourced prototyping.

We’ve worked closely with Kromek, in Sedgefield, County Durham since we started in 2020. Kromek’s background is in radiation detection, working with the medical, power and defence industries. Through this connection, they are working with DARPA, part of the US department of defence, on a system for detection of airborne pathogens, which uses microfluidics to analyse samples. 

Early in the development, to translate a particular process to a lab-on-a-chip, they had to mix small volumes of four different liquids. Using a chain of proprietary components, they simply couldn’t do this. We discussed the process one afternoon in the lab. Sketched it on a whiteboard, modelled it in CAD and 3D-printed it that evening, to be tested the following morning. It didn’t work. But the next one did. We also sent the design out for quotation from other suppliers, and nothing was available within 7-8 weeks, and at a considerable cost. Jamie Marsay, head of biotech, described it as a game changer. After all, if you are in the situation of developing a diagnostic system, trying to detect a virus that is threatening to wipe out half the population of the planet, would you rather test it in eight weeks? Or tomorrow?

So where do we go from here? As well as the more standard customer requests for batches of 1-off, 5, 20 parts, we’ve recently been approached by several companies enquiring about larger batch production volumes up to tens of thousands. So, we can scale up to meet the potential market, we are engaging in processes to improve efficiency by automating our manufacturing and developing our own specific and exact materials. We’ve started down this route with an Innovate UK Smart Grant, along with angel investors backing it. We’ve recently moved into new, larger facilities and the next step is to source more people and upgrade our manufacturing equipment. With our scaled-up production capabilities, we can then expand into ever larger markets.

Rapid Fluidics will be exhibiting at Med-Tech Innovation Expo on 7-8 June 2023 on Stand C20. For more information, please visit med-techexpo.com.