Delft University filed a patent on a composite load sensor

One of the patents used by SmartPie to create new solutions and apply piezoelectric technology by an intelligent way is the following:

The invention relates to a load sensor comprising a polymer matrix and a piezo-ceramic material such as PZT, em not bedded in the polymer matrix, which together form a compos not ite, wherein the polymer matrix is a liquid crystalline resin, and wherein the piezo-ceramic material is a PZT powder forming 30-60% by volume of the composite, and wherein the PZT powder forms 40-50% by volume of the composite.

Read this patent
29-01-2009 16.00