\ OVERVIEW
Tubing and fittings, Replaced.
A fluidic manifold replaces the tubing, tees, unions and fittings between your pumps, valves and detectors with channels cut directly into plastic.
We machine those channels into two or more plates, then fuse the plates into a single block by diffusion bonding — heat and pressure only. Nothing is added at the interface. The finished manifold is one material with one continuous grain, not a stack of parts held together by something else.
That matters more than it sounds. There is no adhesive to squeeze into a 300 µm channel and cure there. No bond line to shed particulate into a reagent path. No glue whose pressure rating falls away as the instrument warms up: published testing on adhesive-bonded thermoplastic chips found seals holding above 5 bar at 25 °C but only 1.6–1.8 bar at 95 °C. A diffusion bond has no such temperature cliff, because there is nothing in the joint but the polymer itself.
Machining also gets you geometry that molding cannot: layer-to-layer crossovers, buried plenums, channels that pass over and under one another inside the block. And it gets you those at quantity one, without cutting a mold.
Channels are cut directly into the plate. Every internal surface is a machined surface, so channel geometry is set by the toolpath rather than by mold release.
\ MATERIALS
Three materials, machined and bonded in house
Most customers arrive with the material already chosen. Below is what each one gives you, and the one thing we would flag at DFM before cutting it.
THE BIREFRINGENCE TRAP
Polycarbonate's stress-optical constant is an order of magnitude above PMMA's and COC's. Residual machining and bonding stress in a PC window will show up as birefringence in any polarization-sensitive or interferometric measurement. If your detection path is polarized, this rules PC out of the window regardless of every other property.
\ FEATURES & PARAMETERS
What we can cut, and what happens when we bond it
Two sets of numbers govern a bonded manifold: the features we machine into the plates, and the thermal cycle that fuses them. The second one moves the first, which is why we publish both.
Machined (CNC) features
WHY WE ASK FOR YOUR|INSPECTION TEMPERATURE
Acrylic expands about 72 ppm/°C. Over a 100 mm manifold that is 7.2 µm per degree — so a 20 °C swing between our shop and your incoming inspection moves the part 144 µm, more than the entire standard tolerance band. We measure at 20 °C and state it on the report. If you inspect somewhere warmer, tell us and we will put the compensation on the drawing rather than arguing about it later.
Diffusion bonding parameters
As-machined is not as-bonded
The bond cycle runs near Tg under load, so the part moves. Anyone quoting you a single tolerance for a bonded manifold without saying which side of the bond it applies to has not thought about it. We inspect the open plates before bonding and the assembly after, and the drawing gets both numbers.
Where channel section is critical, we design in a raised rib slightly proud of the mating face. It concentrates bonding pressure along the seal line instead of over the channel roof, and the section survives the cycle.
What diffusion bonding will not do
It runs hot. Any surface chemistry, immobilized antibody or dried reagent applied before bonding will not survive the cycle — proteins denature and functional groups are lost. If your device needs pre-functionalized surfaces inside a sealed channel, fusion bonding is the wrong process and we will say so at DFM rather than at first article.
It is also slower and more capital-intensive per part than adhesive lamination. What you buy for that is a joint with no third material in it.
\ PROCESS
Seven steps, all under one roof
Steps 02 through 07 are the four-week manufacturing lead time. The clock starts when the design is frozen after DFM, and stops when inspected parts are packed — shipping is on top. Machining, bonding, inspection and packaging are all in house, and nothing in that chain goes to a subcontractor, which is why four weeks is a normal lead time rather than an expedite.
\ QUALITY CONTROL
Inspected before the block closes, and after
Once a manifold is bonded, most of its critical geometry is behind 6 mm of plastic. A meaningful inspection plan has to be staged — which is the single thing that most distinguishes a real QC program for this product from a paragraph about caring for quality.
DIFFERENT PRODUCT, DIFFERENT PROCESS
Microfluidic chips are not small manifolds
Once channels drop below roughly 200 µm and volumes into the microlitre range, the manifold playbook stops working. Micro-milling leaves tool marks the flow can see. Bonding near Tg under 2 MPa closes a 50 µm channel outright.
So we build them a different way — replicated rather than cut, and sealed at lower temperature and pressure with a compression or intermediate-layer bond that leaves the channel section intact.
Moulded COP chip with integrated valve seat — channel scale and bonding method both differ from a machined manifold.
FAQ
Questions engineers actually ask us
