US 12,078,605 B2
Methods of fabrication of nano-sensor and nano-sensor array
Chandra Shekhar Prajapati, Bangalore (IN); and Navakanta Bhat, Bangalore (IN)
Assigned to Indian Institute of Science, Bangalore Karnataka (IN)
Appl. No. 16/756,743
Filed by Indian Institute of Science, Bangalore (IN)
PCT Filed Oct. 16, 2018, PCT No. PCT/IN2018/050670
§ 371(c)(1), (2) Date Apr. 16, 2020,
PCT Pub. No. WO2019/077630, PCT Pub. Date Apr. 25, 2019.
Claims priority of application No. 201741036760 (IN), filed on Oct. 16, 2017.
Prior Publication US 2020/0240942 A1, Jul. 30, 2020
Int. Cl. G01N 27/12 (2006.01); B82Y 15/00 (2011.01); B82Y 40/00 (2011.01)
CPC G01N 27/127 (2013.01) [B82Y 15/00 (2013.01); B82Y 40/00 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method for fabricating a nano-sensor array comprising:
patterning a sensing electrode assembly on a sacrificial layer deposited over a substrate, wherein the sensing electrode assembly comprises a pair of contact pads and a plurality of electrode elements coupled to and disposed between the pair of contact pads;
forming the sensing electrode assembly based on the patterning on a sacrificial layer deposited over a substrate;
removing the sacrificial layer below a portion of each of the plurality of electrode elements to obtain a plurality of suspended electrode elements; and
applying, to obtain a nano-sensor array, a potential difference between the pair of contact pads for a predetermined time to heat the suspended electrode elements to a first predetermined temperature, such as to oxidize the plurality of suspended electrode elements, wherein the potential difference applied between the pair of contact pads is based on Joule self-heating to create an oxide coated suspended electrode element at the first predetermined temperature, and wherein the applied potential difference depends on thickness of the sensing electrode assembly; and
obtaining a pair of electromigrated regions on each suspended electrode element corresponding to the oxide coated suspended electrode element and a notch portion between the pair of the electromigrated regions, wherein the notch portion is to detect a gaseous component in an ambient gas at a second predetermined temperature, the second predetermined temperature being less than the first predetermined temperature, wherein the first predetermined temperature lies in a range of 600-800° C. and the second predetermined temperature lies in a range of 20-50° C., and wherein the nano-sensor array comprises a plurality of nano-sensors.