A heat-activated metal penis which grows to eight inches might help help men with erectile dysfunction, especially those who don't respond to other more conventional treatments.
The bionic penis is made from nitinol (Ni-Ti), a metal alloy of nickel and titanium, which is surgically positioned at the base of the penis.
The inch-long metal coil is attached to an implant which is also inserted inside the penis and from the outside nothing is visible and the 'bionic' penis looks totally normal.
Scientists at the University of Wisconsin are ready to test the device on animals and it could be available to men within a few years.
Asif Muneer from the British Association of Urological Surgeons, said: "There are fewer components than with existing inflatable implants and that reduces the chances of infection. Some patients are not suitable for existing treatments because they have already had major abdominal surgery, say for prostate or bladder cancer, and have a lot of scarring. With this technique, that's not a problem."
Dr Brian Le, from the University of Wisconsin, is the lead scientist working on the project. He said,"The modern era of penile implants has progressed rapidly over the past 50 years as physicians' knowledge of effective materials for penile prostheses and surgical techniques has improved. In the future, prosthesis will have increasing competition from emerging technologies."
"A shape memory alloy-based penile prosthesis represents a promising new technology in the treatment of erectile dysfunction." British Society of Sexual Medicine chairman Dr Geoff Hackett said: "Current implants can be effective but clumsy. So this is potentially exciting development for the future."