A German carpenter has spent the past 20 years developing an idea for a male contraceptive consisting of a switch that sits inside the testicles, in order to control the flow of sperm through the urethra. Having already attained a patent for the product and created a working prototype, inventor Clemens Bimek is now awaiting the start of an upcoming clinical trial on his product.

Made from PEEK-OPTIMA – a polymer that is regularly used to manufacture implants – the so-called Bimek SLV is surgically inserted into the spermatic ducts during a half-hour operation. Once implanted, the switch can be felt through the skin of the scrotum and physically flipped in order to open or close the flow of sperm.

The device is inserted into the vas deferens as a blockade of sorts. When the switch is in the open position, sperm is able to pass through the vas deferens – the duct that conveys sperm from the testicle to the urethra – before exiting the penis via the urethra. However, when the switch is flicked to the closed position, sperm is blocked from passing through, therefore eliminating the possibility of pregnancy arising from sexual intercourse.

Bimek SLV - The New Contraception for Men from Bimek SLV on Vimeo.

According to the manufacturer’s website, the Bimek SLV is preferable to other contraceptive techniques, such as having a vasectomy, wearing a condom or using the female pill, since it offers a solution to many of the drawbacks pertaining to these options. For instance, it provides greater flexibility than a vasectomy, enabling users to control their own ability to impregnate their partner rather than permanently disabling this. Also, unlike condoms or pills, it cannot be forgotten, since it is constantly present within the user.

The device itself is 18 millimeters long (0.7 inches) and weighs just 2 grams (0.07 ounces), with Bimek himself having already become the first person to receive the implant. A clinical trial involving 25 volunteers is now set to begin, in order to test the safety and efficacy of the product.

According to the Telegraph, some experts have raised concerns over the use of the implant for contraceptive purposes. For instance, Wolfgang Buhmann, spokesperson for the Professional Association of German Urologists, has explained that “the valve could cause scarring where it meets the vas deferens,” which could then block the flow of sperm even when the switch is open.