High-Performance, Micrometer Thick/Conformal, Transparent Metal-Network Electrodes for Flexible and Curved Electronic Devices

Metal-network electrodes (MNEs) are excellent substitutes to the brittle and expensive indium tin oxide (ITO) films for flexible and transparent electronic devices. For a high transmittance and low resistivity, highly ordered metal wire arrays with suitable gap and width are essential. Here, high-orderly and dimension-controllable ultrathin/conformal MNEs are fabricated on mu m thick/curved substrate via programmable electrohydrodynamic (EHD) lithography. By employing EHD direct-writing, large-scale high-resolution photoresist micro/nano-pattern can be digitally printed on ultrathin/curved substrates, as the digital mask in chemical etching process. The Au MNEs show transmittance of 94.3% (at 600 nm optical wavelength) and sheet resistance of 36.7 Omega square(-1) with the optimum pattern which can be adjusted by theoretical analysis. MNEs fabricated on ultrathin polymeric substrate (approximate to 1.5 mu m thickness) can even be hanged on a hair. A flexible and transparent touch panel with MNEs exhibits excellent mechanical durability on a smallbending radius. Additionally, the MNEs are mounted on a fingertip as a "fingertip mouse", which is perfectly conformal with fingerprints and can successfully control the computer directly by two fingers. Not limited to planar devices, the MNEs also can be perfectly fabricated on a nonplanar glass and form a transparent conformal heater.