Generation and control of two way shape memory effect for SMA coil spring

There has been no doubt that a closed coil can not be further compressed. We found out that compression of a closed coil is achieved by reversing coil orientation and subsequently extending the coil. The new technology makes many applications of coil springs feasible that have been regarded as impossibility. Control and generation of two way shape memory effect (twsme) of shape memory alloys are taken here as examples.