US Patent 7808156 - Ultrasonic matching layer with nanoparticles

http://ip.com/patent/US7808156

This patent from VisualSonics Inc. teaches how nanoparticles can be used to reduce signal attenuation in ultrasonic imaging equipment. Claim 1 reads:

1. A matching layer capable of use in a high frequency ultrasonic transducer stack having a plurality of layers, the matching layer comprising

a cured matrix material loaded with a plurality of micron-sized and nano-sized particles,

wherein the nano-sized particles prevent settling of the micron-sized particles in the matrix prior to curing, and

the micron-sized and nano-sized particles contribute significantly to the acoustic impedance of the matching layer.