Laser-assisted fabrication of single-layer flexible touch sensor

Abstract

Single-layer flexible touch sensor that is designed for the indium-tin-oxide (ITO)-free, bendable, durable, multi-sensible, and single layer transparent touch sensor was developed via a low-cost and one-step laser-induced fabrication technology. To this end, an entirely novel approach involving material, device structure, and even fabrication method was adopted. Conventional metal oxides based multilayer touch structure was substituted by the single layer structure composed of integrated silver wire networks of sensors and bezel interconnections. This structure is concurrently fabricated on a glass substitutive plastic film via the laser-induced fabrication method using the low-cost organometallic/nanoparticle hybrid complex. In addition, this study addresses practical solutions to heterochromia and interference problem with a color display unit. As a result, a practical touch sensor is successfully demonstrated through resolving the heterochromia and interference problems with color display unit. This study could provide the breakthrough for early realization of wearable device.

Review of Recent Inkjet-Printed Capacitive Tactile Sensors

“…It produces a high-quality pattern; however, the low resolution, required design complexity, inefficient ink consumption and insufficient control of the ink thickness are limiting factors in contemporary usage, particularly for radiofrequency (RF) applications [ 9 ]. Laser-printing technology offers a higher resolution (<10 μm) than inkjet printing and roll-to-roll printing; however, it cannot be used for cost-effective mass production [ 10 ]. Photolithography is a high-resolution technique that have been compatible with rigid substrates; and using some modifications and/or optimization it has also been successfully applied to print the patterns on flexible and easily-damageable substrates [ 11 , 12 , 13 ].…”

“…Materials such as Ag nanoparticles, single-walled C nanotubes (SWCNTs) dissolved in water/ethanol, SWCNT/RuO 2 nanowires and CNT/PEDOT:PSS have been inkjet-printed on various textiles to realize flexible wearable electronics [ 10 , 28 ]. Thin sheets of conductive (e.g., Ag Nanowire) and composite materials have also been in use [ 36 ].…”

Design of Metal-mesh Electrode-based Touch Panel for Preventing Back-surface Touch Error

“…(2,3) In recent years, studies have been actively conducted to utilize metal in a sensing electrode, instead of high-resistance indium tin oxide (ITO), to develop large touch panels. (4)(5)(6) These touch panels are classified as embedded types and include in-cell/ on-cell and add-on types depending on the location of the touch sensor on the display. (7) The typical add-on types used in large panels include an air gap between the panel and the display, and bending occurs when the panel is pressed beyond the limit force.…”

Fabrication of Single-Layer Touch Screen Panel with Corrosion Resistant Metal-Mesh Electrodes

“…(5) The visibility can be improved by a black-oxide treatment to reduce the amount of light reflected from the metal surface. (3) However, the results of studies on improving the corrosion resistance of metal-mesh electrodes in 720 h 85/85 testing (6) are not promising.…”

“…As alternatives, copper or silver-based metal meshes with high conductivity and excellent flexibility have been developed and actively studied. (2)(3)(4) To commercialize an opaque metal electrode using a touch sensor, it is necessary to improve the transmittance and to form a pattern that cannot be recognized. In addition, it is necessary to overcome its sensitivity to the heat and corrosive chemicals used in conventional photolithography processes.…”