US 11,656,193 B2
Self-calibrating polymer nano composite (PNC) sensing element
Yosef Stein, Sharon, MA (US); Seth S. Kessler, Newton, MA (US); and Haim Primo, Ganei Tikva (IL)
Assigned to Analog Devices, Inc., Wilmington, MA (US)
Filed by Analog Devices International Unlimited Company, Limerick (IE); and Analog Devices, Inc., Wilmington, MA (US)
Filed on Jun. 11, 2021, as Appl. No. 17/346,049.
Claims priority of provisional application 63/038,551, filed on Jun. 12, 2020.
Prior Publication US 2021/0389265 A1, Dec. 16, 2021
Int. Cl. G01N 27/20 (2006.01)
CPC G01N 27/20 (2013.01) 20 Claims
OG exemplary drawing
 
1. A self-compensating sensor, comprising:
a sensing element comprising a polymer nano composite (PNC) film;
a plurality of electrical breakout points disposed on the sensing element;
a measurement circuit coupled to the plurality of electrical breakout points and configured to:
measure a plurality of resistance values between a plurality of pairs of electrical breakout points selected from the plurality of electrical breakout points;
based on the plurality of resistance values, calculate a first resistance of a sensing portion of the PNC film exposed to an environment;
based on the plurality of resistance values, calculate a second resistance of a reference portion of the PNC film adjacent the sensing portion; and
determine a compensated resistance by comparing the first resistance of the sensing portion and the second resistance of the reference portion, wherein the compensated resistance is indicative of a sensed condition of the environment,
wherein
each of the first resistance and the second resistance is a contact resistance independent resistance, the plurality of electrical breakout points comprise a plurality of linearly arranged electrodes that comprise at least five consecutive electrodes, and
wherein the sensing portion is disposed between a first pair of consecutive electrodes of the plurality of electrodes, the reference portion is disposed between a second pair of consecutive electrodes of the plurality of electrodes, wherein
the first pair of consecutive electrodes are a pair of inner electrodes among four consecutive electrodes of the at least five consecutive electrodes, and the contact-resistance-independent resistance of the sensing portion is calculated based on at least four resistance values measured between at least four pairs of electrodes selected from the four consecutive electrodes.