SystemTheory said:A quick scan of this site shows a ten pack starts around $49 dollars
http://www.omega.com/toc_asp/subsectionSC.asp?subsection=E02&book=Pressure
Try Trossen Robotics if a flexible force sensor of some sort might also do for your needs.
Strain gauges can be purchased from various online retailers such as Amazon, Digi-Key, and Mouser. They can also be purchased directly from manufacturers or through electronics supply stores.
There are several types of strain gauges available, including foil strain gauges, semiconductor strain gauges, and wire strain gauges. Each type has its own unique properties and is suitable for different applications.
The right strain gauge for your project will depend on several factors, including the type of material being measured, the expected strain range, and the environment. It is important to consult with a knowledgeable supplier or engineer to determine the best type of strain gauge for your specific needs.
In most cases, strain gauges cannot be reused. Once they have been applied and used, they are typically damaged and cannot be used again. However, some strain gauges, such as self-temperature-compensated gauges, can be reused if they are carefully removed and reapplied.
The difficulty of installing strain gauges depends on the specific application and the experience of the user. Some strain gauges can be easily attached with adhesive, while others may require specialized equipment and expertise. It is important to carefully follow the manufacturer's instructions and, if needed, seek assistance from a trained professional.