BCPS Department, Illinois Institute of Technology, Chicago, Illinois 60616, USAThe growing branch of science and technology known as sensors has permeated virtually all professional science and engineeringorganizations. Sensor science generates thousands of new publications each year, in publications ranging from magazines such asPopular Mechanics and Discover to learned journals like the Journal of The Electrochemical Society (JES). The ElectrochemicalSociety ~ECS!, which has declared itself the society for solid state and electrochemical science and technology, and its worldwidemembership, have been vitally instrumental in contributions to both the science and technology underlying sensors. This article isabout a few of the chemical sensors that have evolved, those still now evolving, and the continuing role of ECS in advancementof sensor science and engineering.© 2003 The Electrochemical Society. @DOI: 10.1149/1.1539051# All rights reserved.Available electronically January 13, 2003.