Low temperature chemical sintering of inkjet-printed Zn nanoparticles for highly conductive flexible electronic components

This study illustrates an innovative way to fabricate inkjet-printed tracks by sequential printing of Zn nanoparticle ink and curing ink for low temperature in situ chemical sintering. Employing chemical curing in place of standard sintering methods leads to the advantages of using flexible substrates that may not withstand the high thermal budgets of the standard methods. A general formulation engineering method is adopted to produce highly concentrated Zn ink which is cured by inkjet printing an over-layer of aqueous acetic acid which is the curing agent. The experimental results reveal that a narrow window of acid concentration of curing ink plays a crucial role in determining the electrical properties of the printed Zn nanoparticles. Highly conductive (similar to 10(5) S m(-1)) and mechanically flexible printed Zn features are achieved. In addition, from systematic material characterization, we obtain an understanding of the curing mechanism. Finally, a touch sensor circuit is demonstrated involving all-Zn printed conductive tracks.

Automated summary

This study presents an innovative method for fabricating inkjet-printed tracks using Zn nanoparticle ink and low-temperature in situ chemical sintering of curing ink. Chemical curing allows for the use of flexible substrates that cannot withstand traditional high thermal budgets. A specific acid concentration in the curing ink is found to be crucial in determining the electrical properties of the printed Zn nanoparticles, resulting in highly conductive and mechanically flexible features. Additionally, a touch sensor circuit utilizing all-Zn printed conductive tracks is demonstrated.