I want to use piezoelectric strain gauge sensor to do force analysis and control of mechanical gripper(type of two-piece clip). But my background is control not material, i don't know how to find appropriate piezoelectric strain gauge sensor. I need help, thanks.

 

Here ya go:

http://www.pcb.com/products/browse_productlist.asp?RequestType=Search&CategoryType=Product%20Type&SearchCriteriaWithin=&cboProductType=358&cboMeasurementType=

Not cheap, but real nice stuff. Depending on what you select you may also need a Charge amplifier to go along with it.