Fabrication of High‐Performance Silver Mesh for Transparent Glass Heaters via Electric‐Field‐Driven Microscale 3D Printing and UV‐Assisted Microtransfer

Abstract

nature, and harsh processing conditions of the ITO and the scarcity of the indium limit the further application for the THs. [3,4] As such, recent studies have proposed several emerging materials for the next-generation TCF to replace ITO, including carbon-based materials, [5][6][7][8] metal nanowires (NWs) or nanofibers (NFs), [9][10][11][12][13][14][15] metal meshes, [16][17][18] conductive polymers, [19] and hybrid materials. [1,[20][21][22] However, the cost, mechanical robustness, and trade-off between transmittance (T) and sheet resistance (R s ) of these TCFs remain limited and inconsistent across applications.The R s of carbon-based materials and conductive polymers is higher than that of ITO, [23] which restricts their use in high-performance TGHs. [4] Metal NWs or NFs and metal meshes have been studied extensively in recent years and have been described as the most promising TCF materials due to excellent electrical and optical properties (in some cases superior to ITO). Metal NWs and NFs have been demonstrated as an ITO substitute in flexible optoelectronic applications because of their mechanical flexibility and preferable T-R s trade-off. However, the resulting THs or TGHs have struggled to achieve T > 90% and R s < 10 Ω sq −1 . [24] Hsu et al. reported a high-performance TCF with R s = 0.36 Ω sq −1 at T = 92% by combining mesoscale NFs with metal NWs, [25] and An et al. produced a copper NF with T > 90% and R s < 0.5 Ω sq −1 using electrospinning and electroplating methods. [21] These NWs and NFs exhibit limitations such as excessive surface roughness, low uniformity, high material cost, and unavoidable haze. [13,26] In addition, adhesion between NWs and commonly-employed substrates is often poor, which makes it difficult to use NWs in harsh environments for extended time periods. [27] These characteristics hinder the production of low-cost high-performance TGHs, which require low R s , high T, and strong TCF adhesion.Metal mesh is considered to be an ideal TCF because of its inherently high T, low haze, high electrical conductivity, good mechanical properties, and low cost. [17] The T-R s trade-off in metal meshes can be further optimized by increasing the intrinsic conductivity or the aspect-ratio (AR) of the metal wire Great challenges remain concerning the cost-effective manufacture of highperformance metal meshes for transparent glass heaters (TGHs). Here, a high-performance silver mesh fabrication technique is proposed for TGHs using electric-field-driven microscale 3D printing and a UV-assisted microtransfer process. The results show a more optimal trade-off in sheet resistance (R s = 0.21 Ω sq −1 ) and transmittance (T = 93.9%) than for indium tin oxide (ITO) and ITO substitutes. The fabricated representative TGH also exhibits homogeneous and stable heating performance, remarkable environmental adaptability (constant R s for 90 days), superior mechanical robustness (R s increase of only 0.04 in harsh conditions-sonication at 100 °C), and strong adhesion force with a negligible increase in R...

Preparation of Nano Silver Paste and Applications in Transparent Electrodes via Electric-Field Driven Micro-Scale 3D Printing

“…Aiming at the shortcomings of the existing nano-silver paste and the problems that the existing technology cannot achieve, such as the stable and continuous printing of high viscosity or a high solid content nano-silver paste, we develop a nano-silver paste with a content of 75% by weight, good dispersing properties, and electrical properties. Meanwhile, electric-field-driven (EFD) micro-scale 3D printing technology is used to print the silver paste to verify the printing characteristics of silver paste [33,34]. In this paper, we discuss and analyze the fabrication details and properties of the silver paste and the printing characteristics of silver paste via EFD micro-scale 3D printing technology.…”

Study on the Time-Varying Characteristics of Discharge Plasma in Micro-Electrical Discharge Machining

“…where j is the current density (A/m 2 ), E p is the enhanced electric field (kV/m), and C and D are constant. From Equation (1), it can be found that the current density depends on electric field intensity, the higher the electric field intensity, the higher the current density. Considering the geometrical shape of the micro-peaks, the enhanced electric field at the micro-peaks on the electrode surface can be expressed as follows [19]: E p = U r t 0.75 l g 0.25 (2) where r t is the tip radius of micro-peaks (m), U is the voltage between electrodes, l g is the discharge gap (m).…”

“…In recent years, more and more attention has been paid to precision machining technology and methods [1,2]. As one of the most popular microfabrication methods, micro-electrical discharge machining (micro-EDM) has been widely applied to fabricate various difficult-to-cut materials [3][4][5].…”

Study on the Discharge Characteristics of Single-Pulse Discharge in Micro-EDM

“…With the increasing market demand for miniaturization and the precision of products, micro-processing technology has become one of the important indicators to measure a country's scientific and technological strength [1][2][3]. Micro-electrical discharge machining (micro-EDM) has become one of the most popular microfabrication technologies due to the advantage of machining electrically conductive materials without direct contact [4][5][6].…”