3D printing lends itself to the manufacture of components which are tailored to specific needs of the end user. For example, an early application of 3D printers was in the manufacture of custom hearing aid shells, designed to fit comfortably into the ear of the individual patient. In dentistry, it has been used to create crowns, mouth guards and braces. Applications in the Life Sciences and Medical Device industry continue to grow as the print resolution, and available materials expand. Exotic applications in tissue engineering, with the goal of producing organs and tissues with defined composition, are being explored.
For applications in microfluidics, ALine has developed a series of 3D printed fluidic connectors that integrate with custom microfluidic devices produced with rapid prototyping techniques such as lamination, or micro-machining. By comparison, commercial connectors, such as luer-locks and hose barbs, have only a limited choice in terms of geometry, require a large footprint for multiple inputs, and introduce dead volume into the fluidic network. Some tubing connectors with compression fittings are available with low dead volume, but are priced so high they often cost more than the device itself.
3D printed fluidic connectors greatly expand the options available to bridge the “chip-to-world” interface. The micro-to-macro interface between the microfluidic chip and the supporting instrumentation has always been a difficult engineering problem. This interconnection issue sometimes leads to the assertion that microfluidics really represents a “Chip in a Lab” rather than a “Lab on a Chip”.
With the development of low cost, high resolution 3D printers, the interface problem can be overcome with simple, easily customized connections. 3D printed connectors with multiple inputs occupy a much smaller footprint and minimize the dead volume. Connectors are customized for the specific device configuration to allow 90 degree of co-planar connections. Hose barbs for flexible tubing connections, as shown in Figure 1) and 2), are a typical application and are readily assembled to the microfluidic using biocompatible pressure sensitive adhesives.
The process to produce these connectors is suitable for rapid prototyping and low to mid-volume manufacturing. The turn-around time is typically a few hours because the process does not involve any machining or production of molds. 3D designs are created using computer automated design (CAD)
software. The printer selectively cures 2D layers of a UV resins, building successive layers which produce 3D objects. Multiple resins are available allowing for choice of color, mechanical properties and biocompatibility. Typical batches include 10-20 connectors per 3D print run with scale-up to 100s and even 1000s easily achieved with no change in equipment.
ALine’s approach of combining 3D printed connectors with our proprietary laminate fabrication technology provides design flexibility in the development of custom microfluidic devices. With the advanced 3D printing tools now available, we solve the problem of the “Chip-to-World” interface with customized connectors, tailored to meet the unique design and functional requirements of each microfluidic application.