Louis Caillard | Hummink: How can we leverage AFM-style force feedback to print features down to 100 nanometers without touching the substrate?
00:01:14 - 00:02:22
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How can we leverage AFM-style force feedback to print features down to 100 nanometers without touching the substrate?
Traditional inkjet printing struggles with resolution limits and satellite droplets, while photolithography is too slow and expensive for rapid prototyping of micro-devices. High-precision capillary printing (HP CAP) bridges this gap by adapting atomic force microscopy (AFM) principles into a macro-scale deposition system. By using a quartz tuning fork resonating at kilohertz frequencies, the printer detects the precise sub-nanometer proximity of a glass pipette to the substrate via frequency shift feedback.
Instead of spraying droplets or dragging a physical tip on the surface, the system establishes a controlled liquid meniscus that acts as a physical cushion between the pipette and the substrate. This fluid bridge allows for continuous ink transfer driven solely by capillary forces, maintaining a constant tip-to-substrate distance even when navigating complex, non-planar topologies.
This real-time z-axis adjustment eliminates the risk of collision, making it highly robust for printing complex 2D and 3D geometries on rough or sensitive surfaces. Because there is no mechanical contact or high-pressure ejection, this soft deposition method preserves the structural integrity of both the substrate and the ink.
In this short video, you can learn:
* How AFM-style resonance feedback enables real-time topological adjustment during printing
* The physics of meniscus-mediated ink deposition that prevents substrate collision
* Why frequency-shift tracking eliminates satellite droplets and printing defects
š **Clip Abstract** This clip explains the core physical mechanics of high-precision capillary printing (HP CAP), highlighting its AFM-inspired tuning fork feedback system. It shows how the technology maintains a precise liquid meniscus to print ultra-fine structures on uneven surfaces without physical contact.
#HighPrecisionCapillaryPrinting, #FrequencyShiftFeedback, #MeniscusMediatedDeposition, #NanoscaleAdditiveManufacturing, #PrintedElectronics, #MicroLEDManufacturing
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00:08:20 - 00:09:58
Can we print fully functional carbon nanotube transistors directly onto flexible substrates without photolithography?
Can we print fully functional carbon nanotube transistors directly onto flexible substrates without photolithography?
Integrating nanomaterials like carbon nanotubes (CNTs) into flexible electronics traditionally requires complex, multi-step photolithography that can degrade delicate 1D/2D molecular networks. This clip details how researchers at Duke University utilized high-precision capillary printing to fabricate stable CNT-based biosensor transistors directly on flexible Kapton substrates.
By exploiting the submicron capability of HP CAP technology, the researchers successfully deposited the source/drain electrodes, the semiconducting CNT channel, and the dielectric layer in a fully printed process. The complete absence of satellite droplets allowed for the creation of ultra-narrow gaps between electrodes, which is vital for high-performance transistor operation.
The resulting flexible device demonstrates stable electrical characteristics and mechanical robustness, maintaining performance even after repeated bending cycles. This breakthrough highlights the potential of capillary printing to replace vacuum-based semiconductor fabrication steps for flexible bio-electronics.
In this short video, you can learn:
* The step-by-step printing of electrodes, CNT ink channels, and dielectrics on Kapton
* How the absence of satellite droplets enables sub-micron transistor channel gaps
* The mechanical and electrical stability of fully printed CNT devices under bending stress
š **Clip Abstract** This segment highlights a collaboration with Duke University to print carbon nanotube (CNT) transistors for biosensors on flexible Kapton. It demonstrates how capillary printing achieves the sub-micron electrode spacing required for high-performance flexible electronics without lithographic steps.
#CapillaryPrinting, #CarbonNanotubeTransistors, #SubMicronPrinting, #LithographyFree, #FlexibleBioelectronics, #AdditiveElectronics
00:11:09 - 00:13:15
What are the real-world throughput, viscosity, and particle size limits of sub-micron capillary printing?
What are the real-world throughput, viscosity, and particle size limits of sub-micron capillary printing?
While direct-write nanolithography offers unmatched resolution, industrial adoption is often bottlenecked by throughput, ink compatibility, and nozzle clogging. This segment addresses the critical engineering parameters of capillary printing, starting with a realistic assessment of speed, which ranges from 10 to 100 micrometers per second on rough topographies, up to 1000 micrometers per second on ideal, flat surfaces.
Ink viscosity is a critical factor for fluid dynamics at the sub-micron scale, and this technology demonstrates a highly versatile operating window from 1 up to 10,000 centipoise. This wide range is achieved because the ink transfer is driven by capillary forces at the meniscus rather than high-pressure pneumatic pumping, naturally favoring higher viscosity formulations.
To avoid nozzle clogging, the speaker defines a strict rule of thumb: the suspended nanoparticle size must remain below 10% of the pipette's aperture diameter. This constraint is illustrated through practical examples using 15 to 30 nanometer silver inks and sub-10 nanometer quantum dots, proving the system's compatibility with diverse nanomaterial suspensions.
In this short video, you can learn:
* The speed trade-offs between highly textured substrates and atomically flat surfaces
* Why capillary-driven deposition accommodates an ultra-wide ink viscosity range up to 10,000 cP
* The 10% rule of thumb for nanoparticle size relative to pipette aperture to prevent clogging
š **Clip Abstract** This Q&A segment delves into the practical operating limits of capillary printing, discussing write speeds, viscosity tolerance, and nanoparticle size rules of thumb. It provides essential engineering constraints for scientists looking to scale direct-write nanomaterial deposition.
#CapillaryPrinting, #DirectWriteNanolithography, #NanoparticleInks, #SubMicronDeposition, #AdditiveElectronics, #Nanofabrication