US Patent 7274458 - Adjustment of sensor wavelength using stretched nanoparticle films

http://www.freepatentsonline.com/7274458.html

This patent from 3M is based on the finding that the detection wavelength of optical sensors formed from nanoparticle films may be altered by stretching (or shrinking) the substrate on which the nanoparticles are formed. This can be useful in tuning sensors to particular wavelengths. Claim 1 reads:

1. An optical film having surface plasmon resonance comprising a thermoplastic film substrate and a discontinuous coating of metallic nanoparticles thereon wherein the absorbtion peak maximum of said optical film shifts at least 10 nm as the film is either further stretched or shrunk.