关键词:微机电系统;印刷晶体管;半导体
摘 要:Printed electronics employing solution-processed materials is considered to be the key torealizing low-cost large-area electronic systems, but the performance of printed transistors isnot generally adequate for most intended applications due to limited performance of printablesemiconductors. In this dissertation, I propose an alternative approach of a printedswitch, where the use of semiconductors can be avoided by building mechanical switcheswith printed metal nanoparticles. I provide the rst demonstration of inkjet-printed microelectro-mechanical (MEM) switches with abrupt switching characteristics, very low on-stateresistance ( 10), and nearly perfect o -state behavior with immeasurable leakage withon/o current ratio of 107. The devices are fabricated using a novel process scheme to build3-dimensional cantilever structures from solution-processed metallic nanoparticles and sacricial polymers. These printed MEM switches thus represent a uniquely attractive path forrealizing printed electronics. I will also discuss an inkjet-printed microshell encapsulation asa new zero-level packaging technology. Inkjet-printing of silver nanoparticle ink is demonstratedto form porous microshells through which sacri cial oxide can be selectively removedto release MEMS structures. A second inkjet printing process using ner gold nanoparticleink or polymer is demonstrated to e ectively seal the microshells. This inkjet-printed microshell encapsulation technology is successfully applied to a MEM relay, and is demonstratedto mitigate the issue of contact oxidation. Speci cally, the stability of the relayON-state resistance is dramatically improved by more than a factor of 100.