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Rules of Thumb for Designing $1 Microfluidic Cartridges

 

If your business plan requires your raw microfluidic chip’s cost to remain under $1 to be competitive with existing solutions, then you need to plan for it early in the product development process. Unfortunately, too often we come across microfluidic device developers who learn heart-breaking, nasty surprises regarding the scalability of their multi-million dollar prototypes.

uFluidix’s production team has put together a few rules of thumb for designing low-cost plastic Microfluidics cartridges. If these restrictions are conflicting with your design requirements, then it is recommended to consult with a few lab-on-a-chip manufacturers soon.

Guideline for the design of low-cost plastic microfluidic chips.

  • Keep the width of features (channels, chambers, …) greater than 20 um.
  • Use no more than two layers including one feature layer sealed by a flat substrate layer.
  • Keep aspect ratio (height/width) between 0.5 and 2.
  • Keep features only on one side of a layer.
  • Avoid hard-to-bond plastics such as olefin copolymers.
  • Avoid dissimilar layers.
  • Avoid the need to micro alignment of layers.
  • Avoid drilled or punched ports. Instead, use side access.

A Manufacturer’s 2 Cents on Developing Microfluidic Products

 

Clients have shared thousands of microfluidic designs or products with uFluidix for contract manufacturing. Interestingly the designs can be classified to two types, lets call them Type A or B, based on whether they exploit micron-size specific behavior of fluids or not. These small scale phenomena include surface tension, electrical, magnetic or shear force, etc… which may behave differently in a 30 micron dia. Microfluidic channel compared to a 1 mm dia. channel for similar designs.

Type A devices exploit the micron scale behavior to achieve a novel function. A Type A product offers something new that probably is not feasible if the design is scaled 10 times larger. Type A designs are therefore innovative or perhaps disruptive. On the other hand, Type B devices offer to miniaturize, integrate or automate existing fluidic products or processes. The value proposition for type B products may include “cheaper”, “faster” or “more accurate” words.

Unfortunately, founders of Type B ventures after 1-2 years, or academic researchers of Type B microfluidic devices after 3-5 years face the sad reality that the macro-scale counterpart of their design, also, offers good or even better solution. Type B products have therefore uphill or often fatal crossing of the chasm due to stiff competition from status quo. Below, I would like to bring summary of a typical communication between a manufacturer and a Type B microfluidic start-up venture:

Venture: How much does it cost to purchase 1000 units of the attached design microfluidic device?

Manufacturer: $50 per chip.

Venture: But that is too expensive. This chip is supposed to be disposable; a conventional lab does the same test that our chip does for less than $10.

Manufacturer: If you increase the volume of your order to 100,000 chips then we manufacture for $5 per chip.

Venture: But we have other costs too. This doesn’t make sense.

I have lost count of similar conversations that we have been through, but it easily exceeds several per month.  Looking back, I confidently say that chances are low to hear back from the above Type B prospect!! On the other hand, we have completed hundreds of projects and delivered thousands of chips to type A clients. Several of them well on their path to launch truly novel products with +$100 price tags!!

 

Aarash Sofla, CEO
uFluidix