WHAT IS A BONDED MANIFOLD?

WHAT THEY ARE, WHY THEY'RE IMPORTANT, AND HOW TO TELL IF YOU NEED ONE

*Updated November 10, 2023

If you’ve spent time on our website, you have likely encountered the term “ bonded manifold.”

But what exactly are those, and do you need one?

The field of fluidics often requires smaller components than other industries might need because they serve a unique and specific purpose. These include items such as handheld on-chip detection devices, nano-pumps for continuous drug delivery, and micro-propulsion for functions in the aerospace industry. As a result, bonded manifolds are the best way to address such challenges and provide superior miniature components.

Bonded manifolds contain channels that transport liquids or gases through spaces with no room for valves, hoses, and fittings. They are created from individual layers of plastic with milled fluid channels. The layers are seamlessly fused (or “bonded”) using heat, time, and pressure to form a single piece. External machining completes the manifold by adding porting and mounting holes.

Note: the typical configuration of a multi-layered bonded manifold is a layout of channels in two layers.

Some of these microfluidic devices have different features and channel sizes. Some are under 250 microns to achieve their intended outcome. Traditional multi-layer manifolds, which feature channel sizes greater than 250 microns, are generally classified as mesoscale fluidic devices.

Bonded manifolds offer a variety of advantages for applications in healthcare and the life science among several other industries. Commonly, applications in healthcare and life science typically need fluids to pass through a series of valves, reaction chambers, and other enclosed environments for analysis and other purposes, particularly on the cellular level. These bonded manifolds can contain hundreds of fluid channels in the smallest spaces to increase the likelihood of more accurate, precise, and predictable results.

For applications outside life science and healthcare, bonded manifolds can also simplify complex systems. Through replacing multiple tubes, pipes, and other components, bonded manifolds can streamline certain systems for easier installation and longer lifetimes. Many also find they can also integrate these manifolds more precisely into their respective devices in a "plug-and-play" manner. Most simply fit the manifold into their relevant device without much more hassle in installation.

While not every challenge will call for a bonded manifold as its solution, we urge designers and engineers to consider them for the following reasons:

• Design Flexibility

We offer near unlimited channel configurations.

• Lower Total Cost of Ownership

Compared to multiple drilled manifolds and tubing, bonded manifolds reduce the number of parts, amount of material, weight, and price.

• Reduced Complexity and Component Count

Manifolds offer precise flow control and improve reliability while reducing assembly time and service costs with a single part.

• Complete System Integration

Keep everything in one module and in the smallest possible envelope to keep size manageable.

• Channel Diameter Length

Get unrestricted length to channel diameters.

• Stress Free Maintenance

With little to no maintenance required for manifolds, these systems can run effortlessly. 

For multi-layer manifold designs, double-sided channels are generally the easiest to produce. However, as polymer materials can be stress-sensitive, we recommend full round channels as the best since they have better flow characteristics. In addition, feature spacing can be as low as 1 mm.

Two-layer manifolds can have very flexible channel layouts. However, more complicated manifolds will need special channel layout provisions. Thus, it is important to consider design complexity. Frequently, two less complicated, two-layer manifolds perform better than a single three or four-layer manifold.

However, production fallout rates, design challenges, and bonding complexity can significantly increase the price as the number of layers grows. There is theoretically no limit to the number of layers, although strong practical limitations exist.

For design engineers with limited experience in manifold layout, creating an efficient configuration can be daunting. Variables —including material choice, channel size and placement, and valve and fitting selection — can add complexity. Whether your design is micro or macro, we at Controlled Fluidics can consult with your design team throughout the design process. As a result, we can help you find the best possible design solution while keeping your budget in mind.

If you already have a design and want to give it a virtual test run, visit our partners at Flow Circuits. Their software gives engineers the ability to test in real time their fluidics design and save weeks on their project timelines.

A few limitations exist on designing and machining bonded manifolds, but they can cause some issues if not addressed.

Limitations to projects that we work around:

• Difficulty Sourcing Materials

Sometimes the options are limited to amorphous plastics.

• Cost

Bonded manifolds are more expensive than drilled manifolds.

• Requires Specialized Skills To Create

The process requires specialized engineering skills, which we provide.

We start by machining the source material into the exact configuration the client needs. Next, we bond those pieces together into one solid piece using the appropriate pressure, heat, and time. Then, we finish the manifold by placing mounting and porting holes using external machining techniques.

Our low-pressure bonded channels keep their shape under pressures of up to 150 psi. Generally, the channels are almost invisible and stand up to long-term use.

• Controlled Fluidics proudly has an ISO 9001:2015 registration, and we adhere to ANSI/ASQ Z 1.4 AND ANSI/NCSL Z 540-1-1994.
• We are able to bond injection-molded manifold halves with strength equivalent to the source material.
• We provide both large reservoirs and tolerances as close as 0.015 inches.
• We produce full round channel configurations for best volume and flow. Single-sided “D” channels are available if desired.
• We machine channels that do not crack or warp under stress.
• We can machine threads on the bond line that will maintain their structural integrity through use and time.
• We have detailed experience creating specialized manifolds for several types of industries.

We offer efficient production and delivery as well as competitive pricing.  Expect 4-6 weeks for prototypes and 8-10 weeks for production of finished items.

We have a whole podcast episode dedicated to bonded manifolds and their injection molded siblings. Check it out to find out more about bonded manifolds and how they can improve your systems today!