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Abstract In recent years, inkjet 3D printing has rapidly gained prominence as a disruptive fabrication technique that has witnessed ever-increasing demand in the fields of biomedicine, metal manufacturing, electronics, and functional material production. This innovative approach involves precise deposition of controlled amounts of material onto a moving substrate through a nozzle, achieving impressive sub-millimeter scale resolution by leveraging the concepts of micro-droplet deposition. However, the dynamic nature of the process introduces significant challenges related to consistency and quality control, especially in terms of reproducibility and repeatability. The key input parameters governing this process, such as pressure, voltage, jetting frequency, and duty cycle, are interrelated, entailing the identification of optimal settings in order to realize high-quality jetting. At present, the data collection heavily relies on image-based methods which are inherently slow and often fail to encompass the entirety of the data, making it difficult to determine the relation between the input parameters and jet characteristics. To address this multidimensional difficulty, we developed a unique approach based on light-beam field interruption to collect critical jet data at high speeds. This novel approach collects both temporal and spatial information on droplet evolution, making it a vital tool for enhancing our ability to attain high accuracy and control in inkjet 3D printing. To illustrate the efficacy of our approach, we model the extracted features derived from the process parameters and the extracted data to predict the droplet jetting behavior and droplet size. Specifically, a decision tree classifier is used to predict the jetting behavior and discern between “ideal” and “non-ideal” jetting behaviors. Simultaneously, a linear regression model was employed to predict the droplet size within the “ideal jetting” class based on the interplay of process parameters and the extracted features. The results emphasize the system’s accuracy in capturing the droplet behavior and size using our light-beam field interference sensing module. Furthermore, these findings establish a crucial foundation for the implementation of real-time feedback control loop in the inkjet printing process, promising advancements in adaptability and precision.
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This content will become publicly available on November 10, 2026
Investigation of waveform parameters in inkjet printing of PEDOT:PSS ink for flexible electronics fabrication
Abstract Inkjet printing has emerged as a versatile technique for the fabrication of functional materials towards non-traditional electronics, offering high precision maskless fabrication capability, low material waste, and wide substrate compatibility. However, the realization of high-quality printing of microscale features requires precise control over the jetting behavior and film formation. In this work, we systematically investigate the printing parameters for the PEDOT:PSS ink on the flexible substrates used in wearable and flexible electronics. By exploring the interplay between the printing waveform parameters, such as drive voltage, dwell time, and jetting frequency, we establish a robust operational window enabling stable droplet ejection and tunable deposition. Droplet spacing is further studied to achieve reliable droplet coalescence for high quality fabrication of the continuous patterns with high line resolution and pattern uniformity. Multilayer printing reveals consistent improvements in film thickness and electrical conductivity, with a pronounced enhancement in early layers due to percolation and phase rearrangement. The achieved printing strategy is successfully applied in functional circuit demonstrations, showing excellent electrical stability under mechanical deformation. This work offers a reproducible and scalable printing approach tailored to the PEDOT:PSS inks, providing a technical foundation for the fabrication of high-performance flexible and printed electronics.
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- Award ID(s):
- 2134664
- PAR ID:
- 10656274
- Publisher / Repository:
- IOP Publishing
- Date Published:
- Journal Name:
- Flexible and Printed Electronics
- Volume:
- 10
- Issue:
- 4
- ISSN:
- 2058-8585
- Page Range / eLocation ID:
- 045006
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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