Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published January 1999 | public
Journal Article

Development of tissue-simulating optical phantoms: poly-N-isopropylacrylamide solution entrapped inside a hydrogel


The average turbid optical properties of the N-isopropylacrylamide (NIPA) polymer solution entrapped inside a polyacrylamide hydrogel (called an NIPA/PAAM gel system) were studied using a multiwavelength oblique-incidence reflectometer. The turbidity of such a system can be drastically changed by simply switching the temperature from below the low critical solution temperature of the NIPA, around 33°C, to above. The absorption coefficient and the reduced scattering coefficient were obtained as a function of wavelength for samples with selected NIPA and blue dextran concentrations. It is found that the scattering of the optical phantom comes from the NIPA polymer chains and the absorption from the blue dextran. The turbid optical properties of an NIPA/PAAM gel system can be tuned to simulate biological tissues at a specific wavelength by varying compositions of NIPA and blue dextran and further modified by controlling the temperature.

Additional Information

© 1999 IOP Publishing Ltd. Received 7 April 1998, in final form 23 September 1998. ZH wishes to acknowledge the support in part by the donors of the Petroleum Research Fund, administered by the American Chemical Society and the US Army Research Office under grant no DAAH04-93-G-0215. LVW wishes to acknowledge support in part by the Whitaker Foundation grant and National Institutes of Health grants R29 CA68562 and R01 CA71980.

Additional details

August 19, 2023
October 24, 2023