Bio-inspired surface treatment on touch screen panels (TSPs) for adhesion enhancement

Immersion of substrates in a dilute aqueous solution of bio-inspired building blocks resulted a deposition of polydopamine thin film on the substrate. The Self-polymerization speed measured by ellipsometry was 1.6 nm/hr. Strong catalyst was added in order to enhance the speed. The resulting speed was increased from 1.6 nm/hr to 30 nm/hr. Bio-inspired surface treated PET and ITO-PET substrates with various treatment times were assembled with FPC using commercial acrylic ACF. As a result, adhesion strength between PET substrates and FPC was enhanced dramatically from below 10 gf/cm to over 500 gf/cm even when the treatment time was 5 min. Electrical contact resistance did not show any notable changes. It was presumably due to the sufficiently low thickness (2.5 nm) of bio-inspired thin film on the electrode.