Fabrication of high-aspect-ratio platinum probes by two-step electrochemical etching

Abstract

In this paper, a two-step AC electrochemical etching process was investigated for the fabrication of platinum probes with controllable aspect ratio from 10 to 30, and tip apex radius less than 300 nm. Experiment results show that the shape of the obtained probes is quite sensitive to the etching time of the first step and the voltage applied in the second step. A graphite crucible was used as the counter electrode during etching. It is proved that the shape of the counter electrode also play a key role for realizing high-aspect-ratio probes. The method presented here provides a simple way in the fabrication of micro-tool for the construction of high-aspect-ratio microstructures, especially for the 3D electrochemical micromachining.

Tooling aspects of micro electrochemical machining (ECM) technology: Design, functionality, and fabrication routes

“…The aspect ratio was up to 10, and the taper angle was only 1 °, demonstrating its excellent effects in stray-corrosion suppression. Similar processing performances are achieved using spherical-tip tools (Liu et al, 2015;Yang et al, 2011;Yi and Zhang, 2015). Sub-micron-sized sphere-ended tools were prepared by Wang et al (2015) (Fig.…”

“…A typical tool for electrochemical discharge grinding is shown in Fig. 17 Platinum nano-tip tool (Yi and Zhang, 2015); (e) Carbon nanotube fiber tool (Meng et al, 2020); (f) Graphite tool (Pradeep et al, 2019); (g) Silicon tool ; (h) Molybdenum tool (Arab et al, 2021); (i) Titanium tool .…”

“…Silver and platinum have excellent electrical conductivity, but are expensive and have low stiffness. The use of silver and platinum in the fabrication of sub-micron scale tools has been reported so far (Wu et al, 2013;Yi and Zhang, 2015), but their use is very limited.…”

Rapid Fabrication of High-Aspect-Ratio Platinum Microprobes by Electrochemical Discharge Etching

“…All the experiments were conducted on a vibration insulation stage in order to ensure the stability and consistency of the results. The detailed fabricated process can be found in our previous work [20]. …”

“…We have fabricated platinum probes with aspect ratios from 10 to 30 and a tip apex radius less than 300 nm using a two-step electrochemical etching process [20]. In this paper, the etching process was further investigated and the voltage applied at the second etching step was refined.…”