Mohandas Gandhi may have exhorted us to "be the change we wish to see in the world," but grinders take the concept to a whole new extreme [source: Shapiro]. Impatient for the post-human future predicted by economists and scientists, they've taken to their kitchens and body-piercing parlors to implant off-the-shelf and jury-rigged devices in their bodies.
The risks run high. Take the most popular application of the technique, implanting magnets in the fingertips, which grinders claim enables one to feel magnetic fields [sources: biohack.me; Borland; Popper]. It's a gateway biohack, a way to accustom newbies to the idea of cutting into healthy tissue and implanting foreign objects [source: Popper]. Without legal access to anesthesia, participants find that the very nerve endings that make fingertips (or, as some have proposed, lips or genitals) attractive as an implant point also mean a world of hurt and risk of passing out.
Grinder websites offer lists of body piercers willing to perform certain insertions, but these shops also assume significant legal risks, including possible charges of assault or practicing unlicensed medicine.
But the greater risk stems from improperly bioproofed implants. Failure to render an object or device sterile, waterproof and chemically nonreactive could bring about anything from an immune response to toxic exposure or infection, resulting in hospital stays, loss of life, or limb or neurological damage. To save money, many grinders pool information and resources on websites, order in bulk and bioproof using hot glue or silicone coating [source: Borland].
The chance to explore uncharted territory, to push the boundaries of the possible, holds a dangerous appeal. In that spirit, some garage biohackers are cobbling sensors and electronics into externally worn prototypes that they hope to eventually miniaturize and implant. These include a hat that electrically stimulates the prefrontal cortex, an anklet that vibrates in the direction of magnetic north and a device that works with magnetic implants to provide a kind of echolocation [sources: Borland; Firger; Popper].
Grindhouse Wetware, a small but growing group of basement biohackers located in the Pittsburgh suburbs, claims to be the first to implant such a device. In 2013, they inserted Circadia, a very basic biosensor package, beneath the forearm skin of Grindhouse member Tim Cannon. About the size of an overly thick deck of cards, Circadia accumulates weeks of body temperature data and sends it to a synced Bluetooth smartphone. It's a proof-of-concept for built-in smart watches that might one day display biometrics such as heart rate, body temperature, blood pressure and blood sugar, along with more common information such as time or text messages [source: Firger].