Inkjet vs. Direct Ink Writing (DIW) for Printed Electronics

In printed electronics, two additive technologies often come head-to-head: direct ink writing (DIW) and inkjet. They are both digital and don’t require additional tooling for design changes, but they tackle different ends of the printed electronics spectrum. DIW delivers robust, real-world functional prints — thick, conductive, and reusable with minimal hassle. Inkjet, by contrast, supports high-precision, low-power electronics that are cost-sensitive.

DIW is a digitally driven extrusion process where a precision syringe deposits high-viscosity conductive inks and functional materials layer by layer, following a programmed toolpath. The dispensing unit may use pneumatic pressure, a piston, or a screw-driven system. DIW supports a broad range of materials, from metal-rich pastes and polymers to ceramics and composite inks [1]. 

Inkjet systems eject tiny droplets (typically 0.5-100  pL) of low-viscosity nanoparticle inks via their nozzles, typically driven by piezoelectric actuators. The technology offers ultra-fine resolution, but inks must meet stringent formulation rules: low viscosity (<30 cP), surface tension ~28-42 dynes/cm, and chemically stable particle suspensions.

As the table shows, DIW is the better fit when functional performance and manufacturability are priorities:

• DIW handles screen-printable conductive pastes with 80-90 wt% metal loading, achieving ~10⁷ S/m conductivity, orders of magnitude higher than typical inkjet prints.
• DIW systems work with standard solder pastes (T4, T5), enabling easy attachment of integrated circuits (ICs) and passive components.
• Works equally well on FR1, FR4, ceramics, PET, TPU, or paper, even on fully recyclable boards.
• DIW machines generally have an open ink ecosystem — researchers can experiment with custom formulations without having to source them from proprietary suppliers.
• Prototypes made with screen-printable materials can move directly into mass production via established screen-printing processes.

In practice, DIW systems excel in prototyping wearables, printed sensors, soft robotics, organ-on-chip devices, and other flexible hybrid electronics [2]. These applications benefit from thicker, robust layers with larger amounts of functional material per footprint area [3] compared to inkjet. 

For example, a review [1] demonstrated the use of DIW technology in printing:

• Soft sensors with stable and repeatable performance, such as glove-type strain sensors with 10 integrated gauges, fabricated in under 15  minutes
• High-resolution pressure sensors (100 μm features, 0.3  kPa⁻¹ sensitivity, 0-500  kPa range) by tuning rheology for 50 μm nozzles
• Wearable optical and mechanochromic devices, including photonic hydrogel-based strain sensors with reversible color changes under strain
• Fully 3D-printed optoelectronic and electronic components, such as QDLEDs, organic electrochemical transistors, and triboelectric nanogenerators, showing high transconductance, low operating voltage, and robustness
• Printed antennas and gas sensors with porous metal microparticle arrays and tunable resonant frequencies for wireless and environmental sensing.

Outside of academia, industry innovators like Voltera, have also been printing additive electronics and validating new materials: 

• Printing ECG Electrodes with Biocompatible Gold Ink on TPU
• Developing a Custom Carbon Ink for Printing a Variable Resistor on PET
• Printing a Magnesium Zinc Battery with Saral Inks on PET
• Printing an RFID Tag with Copper Ink on Paper
• …and more

Inkjet printing is the preferred option when:

• Conductivity and layer thickness requirements are modest, such as low-power, low-speed radio frequency identification (RFID) tags or disposable sensors
• Ultra-fine feature resolution (<50 μm), such as for printed thin-film transistors, antenna arrays, or fine sensors
• Low-viscosity materials are required, such as organic semiconductors or aqueous nanoparticle inks

• Low volume R&D projects where production scalability is not a concern

In summary, inkjet is ideal when you need high-resolution patterning with low-viscosity inks and material economy in early-stage prototyping, especially where manufacturability, solderability, and mechanical durability are not the immediate concern.

Choosing the right approach comes down to whether you're optimizing for device performance and manufacturability (DIW) or fine-scale, low-power innovation (inkjet). Each method plays a distinct role in the broader landscape of printed electronics.

Interested to learn more about technologies for printed electronics and how to choose the best technology that suits your applications? Check out the following resources:

• Printed Electronics: What is Inkjet Printing?
• Introduction to Direct Ink Writing (DIW) Printing Technology
• Introduction to Screen Printing

Want to discuss how our DIW solutions, NOVA and V-One can help with your printed electronics application? Book a meeting with one of our technical specialists.

[1] Hou, Z., Lu, H., Li, Y., Yang, L., & Gao, Y. (2021). Direct Ink Writing of Materials for Electronics-Related Applications: A Mini Review. Frontiers in Materials, 8. https://doi.org/10.3389/fmats.2021.647229. 

[2] Hossein Baniasadi, Roozbeh Abidnejad, Fazeli, M., Juha Lipponen, Niskanen, J., Eero Kontturi, Jukka Seppälä, & Rojas, O. J. (2024). Innovations in hydrogel-based manufacturing: A comprehensive review of direct ink writing technique for biomedical applications. Advances in Colloid and Interface Science, 324, 103095–103095. https://doi.org/10.1016/j.cis.2024.103095. 

[3] Tagliaferri, S., Panagiotopoulos, A., & Mattevi, C. (2020). Direct ink writing of energy materials. Materials Advances. https://doi.org/10.1039/d0ma00753f.