Off-the-shelf dispense systems provide a fixed dispense path that is highly accurate and reliable. But for microliter dispense applications, where precision flow control and positional accuracy along complex paths are required, custom automation is essential.
In today’s TechTalksTM blog, AC Automation’s Associate Controls Engineer, Nathan Darkins, describes some of the solutions and customization options for microliter dispense automation. He includes automated fluid dispense technologies from ViscoTec and Nordson, as well as adaptable systems for complex applications.
For a deeper discussion, connect with us to find out how we can tailor our knowledge and expertise to your unique application.
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Engineering Precision for Microdispensing in High-Volume Manufacturing

Microdispensing typically refers to the process of dispensing very small volumes of liquid, usually in the microliter (μL) range or smaller. This can include volumes from a few microliters down to nanoliters (nL) and sometimes even picoliters (pL).
These small volumes present extremely complex challenges for high-volume automated manufacturing. Miniaturization drives the demand for ultra-precise performance in key industries such as electronics manufacturing, medical device fabrication, biomedical applications, optical and display devices, 3D printing, additive manufacturing, and more.
For liquid adhesives, there are many newer options that bond to a wide spectrum of materials. But the reality is that each comes with its own set of challenges. Experience is required to develop dispense methods and processes that address smearing, measuring, and rapid curing. Automated or manual purging, cleaning, and maintenance must also be considered. These and many other interrelated factors have a significant impact on the consistent, successful bonding of components in a high-volume manufacturing process.

This is where AC adds substantial value. We anticipate these complexities and can not only recommend cutting-edge, off-the-shelf dispense technologies but go beyond a system integrator to engineer custom automated solutions.
For example, we can turn to our strategic technology suppliers, like ViscoTec and Nordson, for the best off-the-shelf dispensing systems on the market. But for complex applications, we also engineer advanced calibrated systems that meet the most rigorous dispense requirements. Customizing performance can include greater control of dispense flow, and cleaner beads. We can also target higher repeatability, integrated motion and vision upgrades, increased speed and efficiency, and built-in scalability.
Solving Part-to-Part Variability with Vision-Guided Pre-Dispense Part Profiling

The complexity of the dispense path significantly impacts the type of dispenser chosen for your application. Off-the-shelf dispense systems are designed for uniform, fixed dispense paths. Whereas parts with complex or ergonomic curvatures require motion profiles with more degrees of freedom. Repeatably fixturing these complex components is a challenge of its own.
Part-to-part variability adds another layer of complexity. Each part’s absolute dispense location can be different from baseline coordinates in the system. Unfortunately, a fixed motion path cannot make on-the-fly positional adjustments. Custom engineering is necessary to develop an adaptive dispense system calibrated and guided by advanced vision and motion.
By adding 2D laser profilometer to the dispensing axis, we can measure and update the dispenser for each part’s true position. Using a 2D profile we build a 3D point cloud with the absolute position of every part in relation to the dispense nozzle, regardless of part-to-part variability.
Through vision calibration, we develop an adaptive microliter dispense system capable of adjusting to near-undetectable variations and positional changes in each part’s path and surface.
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Check out LMI’s Gocator series includes 3D smart sensors for locating and positioning accuracy with resolutions down to 2.5 microns
Adapting to Surface Complexity through Synchronous Multiaxis Motion Engineering

Complex surfaces, contours, and curvatures create difficult motion paths for fluid and adhesive dispensing. These paths are even more exacting with microliter dispense and nanoliter dispense applications. For complex parts and geometries, we recommend a custom 3+axis system capable of synchronous movement.
Using an off-the-shelf 3-axis system to dispense on a complex, contoured surface requires fixturing the workpiece multiple times. This is to ensure that the dispenser can reach the entire surface orthogonally. Each time the workpiece is re-fixtured, a separate adhesive bead line is dispensed for each procedure. This means the entire dispense path cannot be seamless. Unfortunately, defects are most prevalent when a bond line is broken into multiple parts.
But by developing a custom 3+ axis motion system, we use a single fixture to eliminate the need for re-fixturing and lay an adhesive bead in one continuous motion to significantly reduce the risk of defects.
To achieve this, we can integrate a single precision motion platform, like PI’s 6-Axis Hexapod capable of up to six degrees of freedom (6DoF). Through this platform, we enable precise, uninterrupted movement across any curve, contour, or surface. We transform the dispense operation from a set of separate manual tasks to a single automated procedure of synchronous movement. The system moves each part into precise orthogonal alignment to the dispenser. The sequence is an uninterrupted continuous flow through all ranges of motion required to complete the part’s dispense operation.
This approach noticeably improves dispense accuracy, efficiency, and quality. Customization creates more design options for the adhesion surface to enable improved dispensing on non-orthogonal curves that span multiple axes. Automation also reduces the human workload previously required to change out fixtures and handle parts in semi-cured states.
Through a multi-disciplined engineering team, we can even support the design of your product. We can simplify its performance in an automated dispense system that scales with your operation.
Nanoliter Dispense Flow & Bead Control with ViscoTec

Once your motion system has the capability required for the complexity of your dispense operation, the next hurdle is producing a consistent bead of adhesive. The greatest driver of this decision is the adhesive type necessary for your assembly.
Through our strategic suppliers, ViscoTec and Nordson, we can develop dispensing solutions that include consistent flow volumetric dispensing, non-contact jetting, and hot melt dispensing.
For fine dispense volumes down to 250 nanoliters, we often turn to ViscoTec’s preeflow® system with eco-PEN dispensers that enable highly precise volumetric dispensing of both 1- and 2-part adhesives. Their proprietary auger technology uses the “endless piston principle” to deliver clean beads and consistent flow control, regardless of back pressure.

ViscoTec’s control module, with digital and analog inputs, can be adapted to almost any communication system. Adaptable control means we can dial in performance quickly, such as making immediate adjustments to dispense speeds. By achieving a high degree of control over microliter dispense flow and speed, we can customize a volumetric system that delivers:
- Dosing precision of ±1% and 99% repeat accuracy
- Dispense volumes down to 250 nanoliters
- Accommodates many different materials including solids-based and shear-sensitive media
- High-dispense pressure independent of input pressure
- Suck-back for high-viscosity materials
EXPLORE
Check out ViscoTec’s preeflow® technology for highly accurate dispensing down to 1 microliter
SEE ALSO: ViscoTec | preeflow®
VIDEO CREDIT: ViscoTec preeflow® on YouTube
As shown above, ViscoTec’s eco-DUO600 is a 2-part volumetric dispenser:
- Smallest dispensing quantity: 0.030ml
- Adjustable dispense flow: 0.6 to 32 ml/min
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Discover the diverse applications suited to ViscoTec preeflow® volumetric dispense technologies.
VIDEO CREDIT: ViscoTec | preeflow® One Brand for All Applications
Picoliter Non-Contact Dispense with Nordson's Gantry System

Precision engineering leaps to yet another level when we move into the realm of picoliter dispensing. For the very smallest delivery of fluid droplets or material beads, seamless performance is required.
Nordon’s off-the-shelf Unity series is a vision-guided, multiaxis gantry system designed specifically for accurate precision dispensing. Their laser-guided system can achieve micron-level accuracy. And it’s great at repeatably following the same dispense path within their absolute coordinate system. Their stable gantry system, equipped with Nordson’s PURJetTM hot melt technology, is adept at non-contact dispensing on uneven surfaces and substrates.
EXPLORE
Check out Nordon’s Unity system with PJ30 hot melt dispenser
VIDEO CREDIT: Nordson Unity Series on YouTube
Nordson’s UNITYMotion™ software lets us quickly pull up and modify the motion control system. This means we can customize their control recipes to create highly repeatable motion paths following the same dispense path within Unity’s absolute coordinate system.
In the extremely small picoliter range, Nordson’s jetting technology is capable of:
- Accurate and repeatable fixed gantry motion
- Non-contact, hot melt dispensing
- Up to 1000 droplets per second with cycles up to 120 times per second
- Accepts low- to high-viscosity materials, including soldering paste
Early Engagements Drive Successful DFM for Improved Microliter Dispense Performance: Are You Ready?
Engineering for precision dispensing requires an expert partner who understands the challenges and nuances of microliter dispense technologies. Knowing how to match products to technologies is crucial for success in a demanding precision manufacturing environment.
By engaging with AC early, we can deliver valuable insights into Design for Manufacturability (DFM) of your product while targeting your dispense automation goals. Our teams consider the correct technologies, adhesives, additives, and curing methods. We share insights on developing improved guidance features for fiducials that improve dispense accuracy during manufacturing.
Whether you need a high-performing, off-the-shelf system, like those designed by our strategic technology suppliers, ViscoTec and Nordson, or a custom build to achieve the highest possible precision and control over complex dispense automation, we can help.
Let’s start the conversation to understand your unique precision dispense application today!