Pulsed electrohydrodynamic printing of conductive silver patterns on demand

Abstract

Pulsed electrohydrodynamic printing (EHDP) is used to fabricate conductive silver patterns with micrometer resolution. The silver ink pendant experiences swelling, pulsation, and ejection under an applied pulse voltage of 20 Hz. The droplet deposition frequency is equal to the applied voltage frequency so that the EHDP can deposit silver ink on demand. A low applied voltage favors uniform and non-scattering silver patterns while a high applied voltage results in ink scattering. Discrete droplets with 45-55 mu m in diameter and continuous tracks with 60 mu m in width are generated by using a 110-mu m-cailber nozzle. The feature size of deposited patterns is about half of the nozzle caliber, and a finer resolution can be achieved with the introduction of smaller nozzle calibers. Furthermore, the appropriate curing condition is investigated for sufficient combustion of ink solvent. The minimum resistivity of 3.3 mu Omega cm is demonstrated for a continuous track cured at 200 degrees C for 10 min. Eventually, several passive electrical components, such as coated resistors, interdigitated capacitors (6 pF), and spiral inductors (0.6 mu H), are successfully fabricated.National Natural Science Foundation of China [51035002]; Chinese Ministry of Education [708055]; Fundamental Research Funds for the Central Universities [2010121039

A Combined Process of Liftoff and Printing for the Fabrication of Scalable Inkjet Printed Microstructures on a Flexible Substrate

“…Table II [42]- [44] lists the comparison of the previously inkjet-printed planar spiral inductor with this paper in terms of their specification and performance. Wang et al [43] II COMPARISON OF THE INDUCTANCE OF THE PLANAR SPIRAL INDUCTOR BETWEEN THE PREVIOUS WORKS AND THIS PAPER presented a printed spiral square inductor with an inductance of 8.9 nH/mm 2 , which contains a 12-turn coil, 220-μm line width, and 100-μm line spacing. Kang et al [44] presented a printed 7-turn spiral circular inductor with an area inductance of around 3.7 nH/mm 2 .…”

“…The improvement can be attributed to the size-scalable characteristic of the CPLoP process, only limited by the capability of conventional photolithography equipment. Wang et al [43] presented a printed interdigitated capacitor with a capacitance of 0.156 pF/mm 2 resulting from the 80-μm finger spacing. In this paper, the interdigitated capacitor with the 10 μm finger spacing can exhibit an area capacitance of 0.43 pF/mm 2 at 10 kHz.…”

Direct Printing and Electrical Characterization of Conductive Micro-Silver Tracks by Alternating Current-Pulse Modulated Electrohydrodynamic Jet Printing

“…E-jet printing is a promising fabrication method to achieve high-resolution printing, since the dimension of emitted droplets is significantly reduced and much smaller than nozzle dimension. E-jet printing has been reported for the fabrication of metallic patterns [24,25] and microelectrodes [26]. Compared with commercialized inkjet printing, there are many issues that remain to be experimentally and theoretically addressed for e-jet printing.…”

Current characteristics of various ejection modes in electrohydrodynamic printing

“…By reducing the capillary-to-collector distance, EHDP can achieve organized fine patterns with good position control in contrast to other conventional electrohydrodynamic deposition such as electrospin with randomly distributed fiber depositions or electrospray with uncontrolled depositions of droplets. This technique has attracted great attention due to its potential in the fabrication of electric circuit, 6 electronics, 7 biocatalyst, 8 and nanogenerator. 9 One of the most important aspects related to EHDP is the liquid ejection mode, of which depends on various factors including material properties and flow rate of solution, as well as the voltage applied.…”