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.