High-Precision Capillary Printing or HPCaP is a unique technology that leverages capillary forces to perform microscale 3D printing. Pioneered by the French-based startup Hummink, it offers users the freedom to deposit any material on any surface with virtually complete design freedom. It delivers unprecedented resolution and precision in micron and sub-micron scale printing, depending on the size of the nozzle used. The unique deposition technology is commercially available in the form of the Hummink NAZCA platform.
How Does HPCaP Work?
HPCaP is a room-temperature direct deposition approach. Based on the general working principles of an atomic force microscope (AFM), except the AFM tip is swapped for a micro-pipette, the micro-pipette can be thought of as a micropen filled with liquid that is attached to a macro-resonator and controlled on a nanopositioning stage.
The macroresonator vibrates at a resonant frequency until it comes into contact with the substrate. When liquid in the micro-pipette makes contact with the substrate, liquid is extracted by capillarity. In doing so, a meniscus forms which is detected by a shift in the resonant frequency.
Patterns are printed and structures created by stabilising the meniscus using closed loop electronics. These work in conjunction with the sample table (controlling X and Y) and micro capillary height (controlling Z). Continuous deposition is achieved via capillary action, with no external forces required. The deposition process is thus extremely gentle and precise.
The oscillating tip adapts to substrate topography, while the micro-pipette diameter (from 50µm down to 100nm) looks after resolution. Similarly, the resonant phase, amplitude and frequency can also be modified to control the feature that is being printed, offering design flexibility.
The pipette tip is filled with your ink of choice to the tune of a few tens of microliters. While this doesn’t sound like much, the amount dispensed in typically in the nanolitre range and a single pipette can deposit hundreds of kilometres depending on the capillary diameter.
HPCaP technology is patented by Hummink and available in their NAZCA system. HPCaP works synchronously with their AI tools such as intelligent trajectory plotting, advanced image recognition and ink monitoring which optimise parameters assuring users achieve unrivalled efficiency and accuracy. NAZCA systems are also calibrated for ink usage ensuring the most efficient use of precious materials.
Materials
HPCaP is suited to use with inks with viscosities up to 100,000 cP. It is compatible with any material e.g.:
- Polymers – PMMA, SU8, PVP, epoxy and more
- Conductive materials – Silver, copper, gold, indium and more
- Nano-materials – carbon nanotubes, graphene, nanowires and more
Advantages Over Other Technologies
Compared to other techniques HPCaP offers:
- The ability to use any material
- The ability to print on any substrate
- No need for photo-masks
- No use of UV light
- No ion or electron bombardment
- No chemical reactions involved
HPCaP vs other Technologies
HPCaP differs from technologies such as inkjet printing in that it is not a drop-on-demand technology. As such it offers superior continuous printing performance, avoiding common defects associated with inkjet printers.
Other technologies rely on electric fields (EHD) or pressure (robocasting) for printing. These technologies struggle to produce sub-micron features (i.e. submicronic gaps) and precisions.
Applications
HPCaP technology is highly suited top uses in:
- Displays
- Sensors and biosensors
- Photonics
- Luxury items
- Electronic packaging
While very capable of fabricating 3D structures, HPCaP is also well adapted to repairing defects in electrical circuits e.g. in display panels or printing complex patterns for decorative applications.
HPCaP facilitated a smooth repair on a colour converter, ensuring high-quality displays and reducing waste with no splashes or satellite drops which can be created using other technologies.
Summary
HPCaP is a versatile microprinting technology able to fabricate structures with resolution in the 100nm range and precision in of the order of 20nm in the XY direction and 5nm in the Z direction. Using only capillary forces enables the technology to go beyond other competing technologies and overcome their shortcomings to produce smooth continuous structures. Furthermore, being independent of an external factor such as UV curing enables HPCaP to be used with virtually any material and substrate combination and topography.