This article presents a new and promising way to design a temperature sensor, which is based on the micellization or aggregation behavior of binary diblock co-polymers of poly(ethylene glycol)-b-poly(N-isopropylacryl-amide) (PEG-b-PNIPAM) and poly(ethylene glycol)-b-poly(4-vinylpyridine) (PEG-b-P(4-VP)). The temperature sensor presents both a lower critical response temperature (LCRT) and an upper critical response temperature (UCRT), where the thermoreversible aggregating,of PEG-b-P(4-VP) and H2O4 is used to control the LCRT, and the thermoreversible micellization of PEG-b-PNIPAM is used to control the UCRT. Furthermore, the LCRT can be altered by changing the H2O4 concentration, and the UCRT can be adjusted by altering the PEG-b-PNIPAM concentration. (c) 2006 Wiley Periodicals, Inc.