How does the concept of change of resistance of a wire when strained (stretched) has been utilized in technology?

Explanation

The concept of change of resistance of a wire when strained has been utilised by engineers
(i) in providing a sense of touch to the robots.
(ii) in making a machine called strain gauge sensor which is used to analyse the stresses and potential flaws in the structure of aircrafts and subnarines. This gauge is also used to measure the forces of blows in contact sports such as karate and football.
(iii) In making a microscopic strain gauge fitted to a tiny catheter. This is used by cardiologists to measure blood pressure at precise locations within the heart.