Microfluidic devices are in demand in the medical industry – according to the Springer Handbook of Nanotechnology, the global market for microfluidics was approximately $3.1 billion dollars in 2015 and is projected to increase to $7.5 billion dollars by 2020. However, support plates and other microfluidic devices can be difficult to manufacture due to their complex geometries, especially 0.5mm wide and 0.3mm deep micro-channels in cylindrical portions of the plates. A big part of the challenge is acrylic material – if milling machines don’t have high enough feed rates, plastic melts rather than cuts, scrapping the part.

Datron vacuum plates and high-speed CNC machining centers can add efficiency to this process. To demonstrate their technology’s precision, company engineers made their own microfluidic support plate. Tom Hanks, application engineer at Datron, briefly describes the process.

“The design engineer has to come up with the micro-channels and sizes,” Hanks says. “Then it’s the machinist’s challenge to add a toolpath to precisely match what the design engineer came up with using computer-aided manufacturing (CAM) software. They create the 3D-modeled part, drawing all the channels in, and then add a toolpath to that 3D model to determine the machining strategy.”

Datron equipment enables microfluidic support plate manufacturing with:

  • Spindle speeds up to 60,000rpm; reduced chip load, tool deflection, heat; efficiently cut plastic
  • Spray-mist coolant systems; eliminate flood-type coolant systems maintenance issues; reduce or eliminate degreasing, disposal costs
  • X-Y-Z probe finds the part; measures part surface; compensates for irregularities ensuring depth of cut and machining accuracy
  • Automatic tool changer (ATC) with up to 45 tool stations detects tool length, breakage
  • 12" x 18" to 24" x 36" vacuum tables provide steady workholding, fast setup of sheet material
  • Pneumatic, short stroke clamps minimize setup times for redundant processes
  • Optional trunnion-style rotary axis provides 5-axis capability

Machine speed, matched with custom-ground tooling, provides glass-like surface finish on acrylic. To avoid the cloudy finish that can result when cutting acrylic, polished-edge tooling delivers a more optically clear finish and Datron offers an entire line of cutters designed specifically for acrylic. Additionally, vacuum plates make job setup quick and can hold entire sheets of material for batch machining of multiple (nested) parts.

“The rate of material removal, because we have all those combined attributes, is much faster,” Hanks says. “We can reduce cycle times for the same part made on a different machine in almost all cases.”

Alcohol, typically used for machining aluminum may soften a plastic’s surface, so, Datron uses an oil-based lubricant sprayed in a fine mist to machine plastic. Once machining is complete the part emerges burr-free and, after a quick cleaning, is ready to go.

Datron Dynamics Inc.

About the author: Mara Bahmer is the editorial intern for Today’s Medical Developments, Today’s Motor Vehicles, and Aerospace Manufacturing and Design.