Microneedle-Based Electrodes with Integrated Through-Silicon via for Biopotential Recording

Characterization of skin penetration efficacy by Au-coated Si microneedle array electrode

“…Other additional advantages of the presented MNA electrode in contrast to wet electrodes are the facts that MNA electrodes can be reattached several times when measuring at different sites of the same sample and can be reused after appropriate cleaning of the dead skin debris. Furthermore, no irritation or inflammation was observed at the pierced sites, which is in accordance with other studies [25,26].…”

“…In contrast to the work of O'Mahony et al [25] or Gris et al [26] who made through-vias to electrically connect the MNA's front side with its rear side (Ag conducting layer in their case), in our case double sided sputtering was used. Since the support plate of a sputtering system was rotating, a good degree of conformal deposition was also achieved on chip edges.…”

“…A mild sterilization and/or grease or skin debris removal by 0.5% NaOH followed by DI water rinse was utilized between the measurements on different substrates. The electrodes were found easy to clean and dry while the approach with metalized vias [25,26] represents a cleaning problem due to poor removal of cleaning medium from the narrow via that could affect the measurement on the long term. An additional advantage of the designed Au-coated silicon dry electrodes is their reusability.…”

Experimental investigation on surface wettability of copper-based dry bioelectrodes

“…Thus, a dry bioelectrode can be used in the long-term recording process without conductive gel and skin preparation, which also has several obvious advantages such as lower impedance variations, smaller electrochemical noise, better stability, and convenient use. Several fabrication methods for bioelectrodes, micromachining such as wet etching processing [9][10][11][12], reactive ion etching [13,14] method [15], and 3D printing [16] have been developed to measure the physiological signal.…”

“…The wet-etching technique was first proposed to fabricate bioelectrodes with surface micro needle structures [9][10][11][12]. Later, Griss et al [13,14] developed the deep reactive ion etching method to fabricate spike electrodes using silicon that was subsequently covered with a Ag/AgCl double layer to reduce electrode interface noise.…”