Titanium hydride nanoparticles and nanoinks for aerosol jet printed electronics

Abstract

Conductive inks commonly rely on oxidation-resistant metallic nanoparticles such as gold, silver, copper, and nickel. The criterion of air stability limits the scope of material properties attainable in printed electronic devices. Here we present an alternative approach based on air-stable nanoscale metal hydrides. Conductive patterns based on titanium hydride (TiH₂) nanoinks were successfully printed on polyimide under ambient atmosphere and cured using intense pulsed light processing. Nanoparticles of TiH₂ were generated by heating TiH₂ powder in octylamine followed by wet ball milling, yielding <100 nm platelets. The addition of a suitable polymer dispersant during ball milling yielded stable colloidal dispersions suitable for liquid-phase processing. Aerosol jet printing of the resultant TiH₂ nanoinks was demonstrated on glass and polyimide substrates, with a resolution as fine as 20 μm. Following intense pulsed light curing, samples on polyimide were found to exhibit a sintered, porous morphology with an electrical sheet resistance of ∼150 Ω □⁻¹.