Aerosol jet printing is an additive manufacturing technology that enables 3D printing of electronics. It has been demonstrated that aerosol jet can print thin films of capacitors, resistors, and transistors on conformal substrate. Here, we present a series of studies on aerosol jet printing of various copper ink formulations for low and high temperature electric application.
An organic-metal molecular ink was developed for low temperature ( < 150 °C) applications. The Aerosol jet printed organic-copper ink would transform into pure copper at 150 °C. The low sintering temperature of the organic-copper ink allows for the usage of polymer with low glass transition or melting temperatures as substrates for printed flexible electronics. The printed copper conductor exhibits a high electric conductivity of 35 MS/m, which is about 50% of bulk copper’s electric conductivity at room temperature.
We also developed another copper ink for high temperature (> 1000 °C) applications. Normally, copper would start to oxidize at 350 °C in the presence of oxygen. Here, we formulated a hybridized copper and graphene ink that can withstand elevated temperatures great than 1000 °C. The printing process integrates copper nanoplate structures with its dopamine counterparts from atomization, resulting in a layer-by-layer transfer of copper which incorporates dopamine in the atomic scale to ensure uniform deposition of conductive copper-graphene circuits after sintering at 750 °C. The printed copper- graphene conductors display a negative temperature coefficient of resistance of -0.07%/°C, suggesting the synergistic effect by the incorporation of graphene into copper material to enhance its electronic hybridization with anti-oxidation stability.
Learning Objectives:
- Participant will be informed about new materials, for printing electronics to operate in extreme environments, developed by the Army Research Laboratory and its partner.
- The Army Research Laboratory is seeking companies (partnerships) to evaluate our newly developed materials.
- The Army Research Laboratory is willing to collaborate with private and public companies and non-for-profits on additive manufacturing research.
