Microneedles electrodes for living cells

This paper shows the technology development of microneedles electrodes for living cell applications. The study includes the fabrication of cantilever electrodes to monitor individual cells. The technology is based on silicon micromachining by combining deep reactive ion etching and focused ion beam (FIB) nanomachining. Cell biology applications require micrometer size electrodes, smaller than living cells (~20 mum), and biocompatible materials. The metal electrode is fabricated in aluminum and passivated by silicon oxide. The opening of the tip electrode by FIB is also performed. Finally, the tip of the electrode is covered by a nanometer thick gold layer deposited by electroless to improved biocompatibility and electrochemical conductivity. The study also addresses questions concerning to the pre-treatment of the aluminum layer before gold deposition in other to improve the adherence and conductivity.