Yes there is. It normally changes its resistance on compression rather than tension, though there may be tension operated versions, and it uses quantum tunnelling. 

The first available version was the "QTC pill".

Availability was difficult a couple of years ago but seems to be improving again...

[Here's one source][1]

[Wiki article][2]

Some background from the [Nuffield Foundation][3]

These are manufactured by [Peratech][4] who now offer a range of form factors for force sensing, as well as custom products.


  [1]: http://www.mindsetsonline.co.uk/Catalogue/ProductDetail/qtc-pill?productID=56087588-e8f8-45ff-9684-36df2937cf9f&catalogueLevelItemID=cdb9823b-8af0-4f00-b707-94b0d7ee8472
  [2]: https://en.wikipedia.org/wiki/Quantum_tunnelling_composite
  [3]: http://www.nuffieldfoundation.org/practical-physics/qtc-%E2%80%93-discovery-novel-material
  [4]: https://www.peratech.com/