Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

The I/O transform of a chemical sensor



Nalin Katta, Douglas C. Meier, Kurt D. Benkstein, Stephen Semancik, Baranidharan Raman


A number of sensing technologies using a variety of transduction principles have been proposed for the purpose of non-invasive chemical sensing. A fundamental problem common to all sensing technologies is determining what features of the transducer's signal constitute a chemical fingerprint that allows for precise analyte recognition. Of particular importance is the need to extract features that are robust with respect to the sensor's age or stimulus intensity. Here, using pulsed stimulus delivery, we show that a sensor's operation can be modeled as a linear input-output (I/O) transform. The I/O transform is unique for each analyte and can be used to precisely predict a temperature-programmed chemiresistor's response to the analyte given the recent stimulus history (i.e. state of an analyte delivery valve being open or closed). We show that the ana-lyte specific I/O transforms are to a certain degree stimulus intensity invariant and can remain consistent even when the sensor has undergone considerable aging. Significantly, the I/O transforms for a given analyte is highly conserved across sensors of equal manufacture, thereby allowing training data obtained from one sensor to be used for robust recognition of the chemical species with another sensor. Hence, this proposed approach facilitates decoupling of the signal processing algo-rithms from the chemical transducer, a key advance necessary for achieving long-term, non-invasive chemical sensing.
Sensors and Actuators B-Chemical


gas-phase chemical sensor, signal processing, modeling, bio-inspired


Katta, N. , Meier, D. , Benkstein, K. , Semancik, S. and Raman, B. (2016), The I/O transform of a chemical sensor, Sensors and Actuators B-Chemical, [online],, (Accessed April 20, 2024)
Created March 13, 2016, Updated October 12, 2021