Choosing the Right Inkjet Printhead for Printed Electronics
- khashayar Ghaffarzadeh
- 22 hours ago
- 8 min read
Author: Kyle Pucci, kyle@imagexpert.com, ImageXpert
The ImageXpert Perspective
Inkjet printing has been around for decades, but in the world of printed electronics it is still an emerging technology — one that is opening doors to applications that traditional coating and deposition methods cannot reach. At ImageXpert, we have had a front row seat to this evolution. For more than 30 years, we’ve helped engineers and researchers understand, test, and optimize inkjet systems. Our equipment is found in hundreds of labs worldwide, giving us the chance to see firsthand what works, what doesn’t, and what separates a laboratory experiment from a production-ready process.
Unlike print shops or graphic arts applications where speed and cost are the primary drivers, printed electronics demand precision and adaptability. The fluids are often unconventional: nanoparticle dispersions, high-viscosity coatings, or conductive inks. The layers can be extremely thin, sometimes just a few hundred nanometers, or conversely quite thick, exceeding one hundred microns. In every case, the choice of printhead determines whether the process succeeds or fails.
Over the years, we’ve worked with companies who are brand new to inkjet, guiding them through early ink trials, waveform optimization, and eventually into pilot production. We’ve also partnered with seasoned electronics manufacturers who are exploring inkjet for the first time as an alternative to films, sprays, or vacuum processes. In all cases, we’ve seen one constant: there is no “best” printhead. There is only the printhead that is best for a specific application.
To understand why, it’s useful to think not application-by-application, but rather in terms of the common printhead selection factors that matter most. Each factor — drop size, viscosity tolerance, durability, waveform control, and speed — plays a different role depending on whether you are coating a battery, encapsulating an OLED, printing a conductive trace, or jetting adhesives.
Drop Size and Resolution
One of the most important parameters in printhead selection is drop size. The size of each droplet directly translates to the thickness and resolution of the deposited layer. In printed electronics, this is often the deciding factor for whether a process is viable.
Take thin film encapsulation for example. This process involves depositing a protective barrier layer that isolates sensitive electronics from oxygen, moisture, or other contaminants. Because the target thickness is on the order of 100 to 300 nanometers, only extremely small droplets — typically in the range of 1 to 3 picoliters — are suitable. Larger drops simply deposit too much material, creating rough or uneven films that compromise performance. Nanoimprint lithography, which is used to create nanoscale features for waveguides in AR/VR displays, has very similar requirements. Here again, uniform layers of resist material must be deposited with precision, and small drops are essential.
Contrast that with battery coatings, where the goal is to create an insulative protective layer. These coatings can be 100 microns thick or more — hundreds of times thicker than an encapsulation film. In this case, the printhead does not need to produce the smallest possible drops. Instead, it must deliver larger droplets consistently, covering wide areas quickly without sacrificing uniformity. Adhesives used for assembly or protective layering fall into a similar category. What matters is not the ultimate resolution, but the ability to jet reliably and consistently with fluids designed for mechanical performance rather than fine features.
The lesson is clear: the “right” drop size is entirely application-dependent. For submicron films, smaller is always better. For thicker coatings and adhesives, larger drops are not only acceptable but often required.
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Viscosity and Particle Handling
Perhaps the biggest challenge in printed electronics is the diversity of fluids. Inks can range from water-like dispersions with nanoscale particles to thick, particle-loaded coatings that push the boundaries of what any printhead can jet. In most other industries, dozens of different printheads might technically “work,” and the choice comes down to cost, speed, or convenience. Printed electronics is different. The margin for error is tiny, the pool of viable options is much smaller, and the needs are completely different from one application to the next.
For thin film encapsulation and nanoimprint lithography, the inks are usually low in viscosity and contain finely dispersed nanoparticles. Jetting them is not especially difficult, but the demand for thin, uniform layers calls for ultra-small drops — often in the 1–3 pL range — and ultra-high consistency. Even small deviations can cause defects that compromise the barrier or feature quality.
At the opposite extreme are applications like battery coatings and adhesives. These fluids are thick, often requiring careful formulation to bring viscosity below the threshold that industrial heads can handle. This threshold is around 80-90cP at jetting temperature, with more printhead options available if you can make it as low as 40-50cP. They may also include particles in the one to three micron range, which dramatically increases the risk of clogging. For these processes, the challenge is not achieving fine resolution, but simply maintaining stable jetting without constant cleaning or downtime.
Not every printhead is built for this. Recirculating designs are often preferred because they keep particles moving across the nozzle plate, reducing the chance of sedimentation and blockage. Heads with more robust nozzle materials are also advantageous, since abrasive or viscous inks can accelerate wear. By contrast, MEMS-based printheads — excellent for producing extremely fine features — may not be durable enough for these kinds of demanding fluids or environments.
Between these two extremes are conductive inks used for printed traces and sensors. They tend to be less viscous than adhesives but contain high loadings of metal nanoparticles. The printhead must be tolerant of these particle-rich dispersions to maintain performance over time. A similar story applies to solar cell and organic electronic inks, which may rely on unusual solvents or binders that interact differently with nozzle materials. In these cases, chemical compatibility becomes just as important as viscosity or particle size.
In short, viscosity and particle handling are where printed electronics often stretch printheads beyond their comfort zones. Success depends not just on whether a head can eject the fluid once, but whether it can do so consistently, cleanly, and reliably over the long run.
Durability and Operating Environment
The operating environment for printed electronics is often very different from that of commercial printing. Some electronics printing may be operated in controlled cleanrooms, but some processes are much more industrial that are far from dust-free. This makes durability a key consideration.
For battery coatings and adhesives, durability is especially critical. These processes often occur in manufacturing spaces where dust and debris are present, and where fluids may be chemically aggressive. A robust printhead that can withstand contamination, be cleaned easily, and continue operating reliably over long runs is worth far more than one that offers the finest resolution but clogs at the first sign of dust.
Thin film encapsulation and nanoimprint are usually performed in more controlled environments, often alongside semiconductor or display processes. Even so, the consequences of contamination are severe. A single particle or dried droplet on a nozzle plate can ruin the uniformity of a nanoscale film. For these applications, durability translates to cleanability and stability, ensuring that the head can operate consistently over long print runs without unexpected failure.
Waveform Tuning
Perhaps the most overlooked factor in printhead selection (until you’ve gotten started) is the ability to finetune it to the needs of your unique process. With inkjet printing, this comes in the form of tuning the waveforms used to eject the drops. Some printheads use easy to interpret waveforms with full editing ability, some use complex waveforms that require training, some don’t let you edit the waveforms at all. Fluids used for printed electronics rarely behave like the water-based inks printheads are designed around. Achieving stable jetting often requires customized voltage pulses, dialed-in with your exact fluid.
For thin films and nanoimprint, where drop sizes are at the picoliter level, even a small deviation in waveform can result in satellites or inconsistent drop volume. Developers in these fields grow to depend on finetuning waveforms on demand, adjusting parameters quickly during ink development. For viscous battery coatings or adhesives, waveform tuning is equally important but for different reasons. These inks may require longer, more forceful drive signals to overcome viscosity and surface tension. Without tuning, drops may form inconsistently or not at all. Conductive inks add another layer of complexity: nanoparticle dispersions can behave unpredictably under electrical stress, and waveform adjustments are often necessary to maintain consistent performance over time.
The bottom line is that waveform flexibility should be a core criteria in printhead selection. The best head in the world is of little use if you cannot adapt it to your fluid. Printed electronics is a space where custom waveforms are not optional — they are the rule.
Print Speed?
In most printing industries, speed is one of the first factors considered. In printed electronics, it is often the least important. Almost every industrial printhead on the market today can operate faster than the process itself requires. For these applications, the limiting factors tend to be substrate preparation and post-processing (such as curing or sintering), not the maximum speed of the head. For most developers, the assurance that “any head is fast enough” is a relief, allowing focus to remain on the parameters that truly matter: drop size, fluid compatibility, durability, and waveform control.
Conclusion
When choosing a printhead for printed electronics, it is tempting to search for a single “best” option. In reality, printed electronics is not about finding the fastest printhead or the one with the highest resolution on paper. It is about matching the head to the demands of the ink, the layer, and the environment. A class of applications demands heads capable of producing ultra-small, highly uniform drops. Others require durability and viscosity tolerance, even at the expense of fine resolution. Others demand compatibility with nanoparticle dispersions and other unique materials. The decision comes down to understanding the selection factors that matter most — such as drop size, fluid handling, durability, waveform control — and aligning them with your application.
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Who is ImageXpert?
At ImageXpert, we don’t sell printheads. We test them, push them to their limits, and help developers understand which ones will work for their process. That neutrality is what allows us to provide objective advice. With decades of experience and equipment installed in labs around the world, we’ve seen the evolution of printhead technology from early piezo designs to today’s recirculating architectures. We know which heads thrive in particle-loaded environments, which excel in submicron precision, and which offer the flexibility needed for waveform development.
More importantly, we’ve walked alongside companies through every stage of adoption. We’ve helped researchers run their first ink trials. We’ve assisted startups in scaling from prototypes to pilot production. And we’ve supported large manufacturers exploring inkjet as a cost-effective alternative to traditional films or spray coating. This broad experience gives us a perspective that few others can offer: not only what works on paper, but what works in practice, in real-world labs and factories. We look forward to helping you select the right equipment for your application!
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