Engineers at the University of California have implanted tiny wireless sensors in rats to monitor muscles and nerves. (Courtesy of Ryan Neely/University of California)

Sensors the size of a grain of sand could one day explain what’s happening in your body from the inside out.

Engineers at the University of California, Berkeley, implanted wireless sensors measuring just one millimeter cubed  in the muscles and nerves of lab rats, then used ultrasound waves to extract information from them about how well those parts of the body are functioning.

The benefits of the technology for humans, while still largely hypothetical, are promising. The sensors could allow physicians to monitor the health of organs, create new therapies for neurological disorders, and help the physically impaired to control prosthetics.

While chips have been implanted in humans and other animals before, these sensors mark a significant improvement because they are small, wireless, batteryless, and could last in the body for years without degrading, said Michel Maharbiz, the associate professor who devised and studied the sensors alongside neuroscientist Jose Carmena.

“Hopefully the [tiny sensors] demonstrate a new direction for the field, and then you could build the consensus that’s needed to drive these forward,” Maharbiz said.

And just how long until these chips are installed in humans?

“Years and years,” he said.

The sensor requires further development and rigorous safety testing before a few people could even take part in a clinical trial, he said. That all requires ample time and money.

The research was funded in part by the Defense Advanced Research Project Agency, or DARPA, which heralded the technology as having significant scientific and health-care implications if researchers can eventually use it to communicate with the central nervous system and elaborate network of nerves that control the human body. Beyond uses in medicine, the sensors could also act as a next-level health monitor for fitness enthusiasts.

This, Maharbiz emphasized again, is years away.

“It’s certainly true [new technologies] make it into humans, but it just takes time,” he said.

Whether people want the technology may be a different story. As my colleague Hayley Tsukayama reported last week, new data from the Pew Research Center found people were generally wary of biomedical technology and implants that aim to enhance the human body. Among those technologies where apprehension exceeds excitement: brain chips.

“It’s pretty clear that thinking about these ideas in connection with helping people with medical issues is different than taking people who are otherwise healthy and enhancing their abilities,” Cary Funk, Pew’s associate director of research on science and society, told The Post.

Read more from The Washington Post’s Innovations section.

Farming on the moon and meat grown in a lab: Six thoughts on the future of food.

Humans once opposed coffee and refrigeration. Here’s why we often hate new stuff.

Why people mourn the death of the VCR and other outdated technology