The male contraception that makes you infertile by flicking a switch

Invented by a German carpenter, the implant will be trialled in 25 men this year

A form of male contraception has been invented that allows a man to make himself temporarily infertile by simply flicking a switch.

German carpenter Clemens Bimek claims the invention, an implanted valve to stop the flow of sperm, will revolutionise contraception.

The surgery required sees a valve, less than an inch long and weighing less than a tenth of an ounce, implanted on the vas deferens, the ducts that carry sperm from the testicles.

(Bimek SLV)

This valve can be operated by a switch that a man can control from the outside of his scrotum’s skin, which will stop and resume the flow of sperm as desired.

Mr Bimek has so far only implanted the contraceptive in himself but will begin trials with 25 men this year.

Hartwig Bauer, a urologist who led Mr Bimek’s surgery, told Spiegel magazine that such an innovation would be a safer bet than getting a vasectomy, due to the number of men who look to have them reversed.

“A third of patients want to have the operation reversed later, but it doesn’t always work,” he said.

However other doctors have been less keen to praise the implant, with Wolfgang Buhmann, spokesman for the Professional Association of German urologists, concerned about potential scarring that would stop sperm flowing altogether.

Anneke Loos, head of a testing centre for medical products in Hannover, expressed concern over potential clogging in the valve.

"Other implants made of this material have been well tolerated elsewhere in the body,” she said.

“The question is whether it will cause problems when it is implanted in this area.”

Mr Bimek told Spiegel that his inspiration for the valve came when watching a documentary 20 years ago.

Once he found that no patent had been filed for one he set upon developing his own.