A man with metal horns protruding from his forehead and a split tongue poking out between his teeth advanced toward me with a scalpel. “I’ve never done this before,” he joked, inching closer.

A full-sleeve tattoo snaked out from beneath his black T-shirt, extending from a demon on his bicep to a skull on his fist. My eyes darted between skull and scalpel, then instinctively shut as I cringed, bracing for contact. Zack Watson, the inked-up body modification artist I’d hired — and drove seven hours from New York City to see — was about to sew a magnet under my skin.

The entire procedure took two minutes: Watson rubbed iodine on my right ring finger for sanitization, sliced open the soft pad of my fingertip, spread the edges of my skin apart with a curved hook and inserted a gold-plated, silicone-coated magnet the size of a pencil eraser inside with tweezers.

He then wiped up the blood with gauze, tied my finger shut with two stitches, and told me how to take care of the wound in the weeks following to make sure my body didn’t reject the magnet as it healed.

Zack Watson sews a magnet into Jennifer Booton’s finger Scott Goldsmith

Watson, who has several implants of his own, including silicone rectangles in his forearms that make his skin feel riblike, has been putting magnets and chips in people for three years at Ice 9 Studio, a tattoo and piercing parlor in Pittsburgh’s South Side Flats (though he recently left to open his own shop). His efforts are part of an underground movement in which people get implants as commonly as others get tattoos.

Interest has been spreading, with Watson quickly working through his latest supply of magnets. One woman recently traveled to Ice 9 Studio from Australia for a radio-frequency identification chip she uses to store personal information. Watson’s business frequently comes through his connection to Grindhouse Wetware, a Pittsburgh-area startup of “biohackers” who aim to augment the human body with technology. If successful, they’ll be at the vanguard of a movement called transhumanism that experiments with how technology can give us new, almost-superhuman, abilities.

Is biohacking the next phase of human evolution?

Biohacking enthusiasts have tinkered with electronic tattoos and subdermal — underneath-the-skin — implants for two decades, sharing their efforts in videos on YouTube and internet forums to spread and encourage innovation. Proponents believe smart implants represent the future of wearable technology, potentially making humans healthier and more efficient while providing new opportunity to consumer-technology companies such as Apple Inc. AAPL, -4.19% and Alphabet Inc. GOOGL, -3.45% GOOG, -3.42% that are investing heavily in technology that could revolutionize health care.

“You’re talking about extending your body to its maximum potential — and then beyond,” said Grindhouse co-founder Tim Cannon.

Watson and his 6-month-old son, Thor, in Pittsburgh Scott Goldsmith

Big tech companies see big opportunity

In the late 1990s, an Englishman named Kevin Warwick was among the first people to put an RFID chip under his skin, letting him turn lights on and off and interact with appliances by scanning the chip with computer-controlled devices. Today, many people — including Warwick — are pushing that concept even further.

Amal Graafstra, who has tinkered with biohacking for at least a decade, is developing a smart gun that would use an RFID chip to ensure that it only fires in the hands of its owner. French tattoo artist JC Sheitan Tenet, who lost his right arm as a child and had to relearn how to draw with his non-dominant left hand, was recently fitted with a working tattoo machine prosthetic so he could resume work with his dominant hand.

French tattoo artist JC Sheitan Tenet shows off his working tattoo machine prosthetic arm. Lynn

Neil Harbisson, who is colorblind, has an antenna in his skull that lets him “hear” color through audible vibrations. The Massachusetts Institute of Technology in partnership with a research arm of Microsoft Corp. MSFT, -3.29% recently developed a device called DuoSkin that looks like a metallic tattoo and duals as a trackpad for mobile devices. And Warwick is developing brain implants that can help predict and even alleviate tremors associated with Parkinson's disease.

Cyborg culture still flies largely under the radar, but investors and corporations have begun to take notice, funding and building products inspired by many of the same ideas. Much of the mainstream investment so far has focused on tracking and improving health.

Google, for example, is working on a glucose-monitoring contact lens. MC10 recently released a smart Band-Aid-like adhesive called BioStamp Research Connect that helps researchers monitor heart rates and movement. Biotricity is developing a wearable called Biolife that can monitor heart rhythm, respiration, calories, temperature and physical activity while attached to a shirt or sports bra.

Grindhouse, meanwhile, is building an implantable device it calls Circadia, which records health data and transmits it via Bluetooth to Android devices. Grindhouse argues subdermal devices can collect more accurate data than devices that only sit atop the body, such as Apple Watch and Fitbit. It also believes that software currently being developed by other companies, such as Cisco System Inc. CSCO, -2.64% , will make it easier to sift through and make sense of that data, helping doctors spot long-term health trends and perhaps one day even predict disease before symptoms appear.

All of these predictions come as global adoption of wearables is forecast to boom. Juniper Research, which tracks consumer technology trends, expects world-wide wearable shipments to reach 420 million by 2020, more than four times the 80 million shipped in 2015. A similar surge is predicted for medical devices, with shipments projected to triple to 70 million over the next four years.

By 2020, a third of health/life sciences and consumer product companies will begin to develop the first wave of products that integrate the human body with technology, according to recent predictions published by IDC, which tracks the consumer tech industry. IDC is referring to this industry as “augmented humanity,” and predicts the concept will go mainstream by the middle of next decade.

“The next four years are the ‘proto’ period where we’ll see proof of concept/prototype offerings,” said IDC chief analyst Frank Gens. “And the first Amazons, Googles, and Facebooks of the next era are likely to emerge.”

The increased interest is making it easier for companies to connect with potential investors. Grindhouse says it has been approached by several venture capitalists and physicians who have expressed interest in its work, though it declined to name them. Y Combinator, a Mountain View, Calif.-based accelerator of early stage startups, recently added human augmentation to its top-ten list of favored startup types it is seeking for investment opportunities.

Many of the more established companies MarketWatch reached out to for this story — including Apple, Fitbit FIT, +0.15% and Google — declined to comment, citing policies not to discuss future products or strategy. But many of their recent investments and products have illustrated interest in health technology and human augmentation.

In March, Apple launched CareKit, a platform that hosts apps designed to analyze health data produced by its smartwatch. The iOS app One Drop tracks glucose levels, food intake, medicine consumption and activity for patients with diabetes. Alphabet, meanwhile, went through a massive organizational restructuring in 2015 so it could invest more freely in experimental endeavors, including those in life sciences, such as its smart contact lenses.

Cisco was one of the only legacy companies that agreed to comment on this story, telling MarketWatch about an industrial-grade software platform it’s developing that would tie a broad spectrum of health data, including data from wearables, together for doctors in the cloud.

“Any data generated from those devices…and anything [a user does] across the continuum of care, will be sourced and put in the platform,” said Barbara Casey, who leads enterprise health care initiatives at Cisco. It will give doctors a “much more complete picture” of a patient, she said.

Battling regulation — and cultural taboos

To be sure, experts see speed bumps along the way. Companies “can see the potential profit,” said Warwick, whose experiments are funded by grants provided through Reading University, but there’s still consumer resistance to more invasive health technology, and companies may want to see more social acceptance before committing further.

Juniper, which helped coin the term “invisibles” in reference to dermal and subdermal wearables, expects the market to remain “embryonic” for a while, partly because most people haven’t thought twice about putting technology in their bodies.

Amal Graafstra's implanted RFID chips, seen on a 2006 on a 2006 X-ray. dangerousthings.com

Some of that may be due to dissatisfaction with current options. In 2014, Endeavour Partners estimated that activity trackers get abandoned after an average of six months. Users may be expressing fatigue with the overabundance of data produced by such devices without enough context telling them what it all means to their long-term health, said Juniper analyst James Moar.

Others believe medical-grade or invasive devices might end up being too expensive for many consumers, though that might be addressed if doctors write prescriptions for FDA-approved tech implants the way they might for, say, reading glasses. For the vast majority of people, though, current wrist-bound devices like Apple Watch, while they may be imperfect, are likely accurate enough, said Kate McCarthy, a Forrester Research health care IT analyst.

Also Read:Brain implants would make ‘The Matrix’ come to life

“It’s OK that there’s a degree of inaccuracy,” said McCarthy, who uses Apple Watch to manage her symptoms from Addison’s disease, a degenerative disorder that occurs when the body fails to produce sufficient levels of the hormone cortisol. “It’s close enough for me to do the things I need to do.”

There are also regulatory concerns. In July, the U.S. Food and Drug Administration said it won’t scrutinize “low risk,” outside-the-body, health wearables that don’t purport to produce professional-grade medical data. But implants that claim such accuracy would likely face rigorous approval processes. Invasive products — those that “penetrate or pierce the skin or mucous membranes of the body,” according to the FDA — and those that claim to help treat a specific medical condition, could take months or even years to reach consumers.

Still, advocates for the biohacking and transhumanism movements say consumers and Fortune 500 companies are warming to the potential of next-generation, health-monitoring devices. Ryan O’Shea, Grindhouse’s head of media, believes demand will increase as devices get more advanced and personal and the mechanisms to understand health data are improved.

“ “We’ve been directing human evolution since we invented fire.” ” — Ryan O’Shea, Grindhouse Wetworks

“When you have a device that’s going to be able to get accurate blood oxygen levels, blood pressure, heart rate, and then kick it out to your devices — perhaps even alert a doctor — people are really going to see the benefit,” he said. “It could save a life.”

Also See: Biohackers implant computers, earbuds and antenna in their bodies

That would mean an end to “measuring your activity for activity’s sake” like people do now with Fitbits, said MC10 co-founder Rooz Ghaffari. Increasingly, data will be gathered with purpose, which will help doctors provide better preventive care and help people manage their disabilities, he said.

Warwick and O’Shea both believe technological advances will give humanity an evolutionary boost similar to that provided by eyeglasses, pacemakers, prosthetic limbs and medicine. Warwick, for example, is studying how ultrasound might be used to help blind people navigate their surroundings.

“We’ve been directing human evolution since we invented fire,” said O’Shea. “The whole medical industry is a biohacking industry. We just don’t call it that.”

A ‘sixth sense’ for things others can’t feel

After Zack Watson finished implanting my magnet, I tested his work by lifting a needle with my finger’s magnetic pull. It dangled there, and I laughed, amused that I could now do magic tricks and freak people out at bars. Later, in a dingy unfinished basement in the unassuming home Cannon rents 30 minutes from downtown Pittsburgh that serves as Grindhouse’s lab, Cannon sent Morse code messages to my magnet using a device called Bottlenose his company developed that emits vibrations through electromagnetic fields.

The magnet’s purpose, I quickly realized, was not to pick up small metal objects and amaze my friends -- though I still do that -- but to sense things others can’t.

Jennifer Booton feels magnetic pulses in her finger in Grindhouse’s basement labs. Scott Goldsmith

Steve Haworth, a pioneer of subdermal implants who sells the specially coated magnets to body artists and does his own body modification work in Phoenix, says the magnetic implant grants its users a sixth sense, allowing them to detect waves emitted by motors and electrical equipment that are invisible to others. My finger often tingles near microwaves, laptops and smartphones.

Also Watch:Bodyhackers implant RFID chips to customize themselves

My implant officially makes me part of the cyborg culture, Cannon assured me. He encouraged me to participate in web forums and Facebook groups and share my healing progress and experiences, saying that exchange of data is crucial to the movement’s advancement.

“ “You’re talking about extending your body to its maximum potential. And then beyond.” ” — Grindhouse Wetworks co-founder Tim Cannon

I sat with Cannon as his team gathered in his basement and a few others from around the world tuned in via Google Hangouts for their weekly meeting. They were dissecting the various components of their ambitious biotech projects when we launched into a discussion about the far-off future of wearable technologies. They told me how they imagine a world in which implants are so in tune with our bodies they’ll engage a home’s heater before a user even realizes they’re cold. Screens, they imagine, might just be projections of our own imagination, placed in our line of vision by chips in our eyes.

These aren’t just lunatic predictions from a group of science fiction fans: Piper Jaffray analyst Gene Munster recently predicted something similar, saying in a note to clients this summer that he believes some sort of wearable — likely glasses or contact lenses — will “replace the majority of screens in our everyday lives” within 10 years.

“There’s a lot of money to be made just around the corner,” said Marlo Webber, a Grindhouse engineer who moved from Australia to Pittsburgh earlier this year to be closer to the action.

“The possibilities,” Cannon said, “are endless.”

This story was first published on Nov. 15, 2016.