Ethan Secor | Iowa State University: What are the advantages of using closed-loop control in aerosol jet printing to mitigate long-term process drift?

How can an aerosol printing system deposit 20-micron lines through a 100-micron nozzle without ever clogging?

Ethan Secor details the fundamental physics of Aerosol Jet (AJ) printing, highlighting the process of atomizing liquid inks into 1 to 5-micron droplet mists. These micron-scale droplets are suspended and transported via a carrier gas directly into the printhead.

The core of this technology lies in the dynamic interaction between the carrier gas and a surrounding sheath gas. By introducing a clean sheath gas ring, the system constrains the aerosol stream to the center of the nozzle, preventing physical contact between the ink droplets and the nozzle walls.

This unique aerodynamic focusing allows operators to print features dramatically smaller than the nozzle aperture itself. For instance, a 100-micron nozzle can easily generate 20 to 30-micron feature widths, completely bypassing the clogging issues that plague conventional micro-dispensing systems.

In this short video, you can learn:
* How 1-5 micron droplets are generated and transported using carrier gas dynamics
* The mechanics of sheath gas focusing in preventing nozzle clogging and wear
* The relationship between physical nozzle diameter and the final printed line width

📋 **Clip Abstract** [This clip explains the foundational mechanics of aerosol jet printing, focusing on how a carrier and sheath gas system aerodynamically focuses droplets. It demonstrates how fine lines are patterned without physical nozzle-wall contact, reducing contamination and clogging risks.]
🔗 Link in comments 👇

Why do high-vapor-pressure solvent inks cause "false negative" deposition failures in aerosol jetting?

Ethan Secor examines the rapid evaporation thermodynamics governing aerosol droplets during flight. Because of their high surface-area-to-volume ratio, 1-5 micron droplets evaporate on a millisecond timescale when exposed to dry sheath gases.

If an ink dries out too quickly, the droplets lose their mass and inertia, failing to impact the target substrate—a phenomenon known as a "false negative" deposition. To counter this, ink formulators must incorporate a 5% to 20% concentration of a low-volatility co-solvent.

However, balancing this solvent ratio is critical. An excess of low-volatility co-solvent yields a wet, low-viscosity deposition that becomes highly unstable under the high-velocity (50 to 100 m/s) carrier gas jet, leading to splattering and reduced feature resolution.

In this short video, you can learn:
* The sub-millisecond evaporation thermodynamics of micron-scale droplets in flight
* How to resolve "false negative" printing errors using low-volatility co-solvents
* The hydrodynamic balance required to prevent deposit instability under high-velocity gas jets

📋 **Clip Abstract** [This clip explores the rapid drying physics of aerosol droplets and the critical role of ink formulation. It highlights how balancing low-volatility co-solvents is necessary to avoid both complete dry-out and wet film displacement.]
🔗 Link in comments 👇

How do you choose between ultrasonic and pneumatic atomization for high-viscosity electronic ink printing?

Ethan Secor compares the performance envelopes, viscosity limits, and operational scales of ultrasonic versus pneumatic atomizers. Ultrasonic atomization excels in low-volume, high-precision environments, typically handling low-viscosity fluids up to 10 centipoise.

Conversely, pneumatic atomizers leverage high-pressure gas flows to handle moderate to high viscosities, comfortably processing fluids up to 100 centipoise and even solvent-free UV-curable acrylates. This capability is critical for depositing structural dielectrics and functional epoxies.

The choice between these two methods dictates the system's throughput, minimum line width, and overall reliability. Understanding these scaling behaviors allows materials scientists to formulate inks that align with target resolution and volumetric deposition requirements.

In this short video, you can learn:
* The operational differences and volume capacities of ultrasonic and pneumatic systems
* Viscosity limits and material constraints for printing solvent-free UV-curable polymers
* The trade-offs between high-resolution precision and maximum volumetric deposition rates

📋 **Clip Abstract** [This segment provides a detailed comparison of ultrasonic and pneumatic atomization techniques used in aerosol printing. It outlines critical trade-offs in ink volume, viscosity ceilings, and line-width resolutions to assist in system selection.]
🔗 Link in comments 👇