# A new approach of electrochemical etching fabrication based on drop-off-delay control

### Abstract

W-Pt micro-nano-thermocouple is a brand new sensor for intracellular temperature measurement. As a nanodevice, it is based on the electrochemical etching method of which the shape is directly related to the performance. Although much research has been done on how to control the shape of the tungsten tip through electrochemical etching method, preparing different shapes requires different fabrication methods. In this article, we proposed a flexible and general control method which can fit all the fabrication methods by merely modifying the software. Moreover, this method based on drop-off-delay time control is capable of controlling the duration of the electrochemical reaction during the final formation of the tungsten tip. Based on this method, the cone angle can be set to any value from $5^{o}$ to $30^{o}$ with the radius of curvature maintaining from $2 nm$ to $5 nm$. Additionally, the sophisticated fabrication of W-Pt micro-nano-thermocouple was designed to be automatically completed by three workshops in batches. The efficiency and uniformity of W-Pt micro-nano-thermocouple fabrication were well improved.

Publication
Review of Scientific Instruments