To be honest, self-powered wearable sensors (piezoelectric/triboelectric/TENG-based) are a real reality.

And yes, it’s natural to be surprised when you first hear about this and think, “Our bodies are chargers?”

This technology converts the mechanical energy generated by the human body’s movements (walking pressure, joint movement, vibration, heartbeat, blood flow, etc.) into electricity, and the research community is already quite mature.

To summarize three major methods:

1) Piezoelectric — “Electricity comes from pressing.”
“Pressure and vibration,” such as foot pressure, knee bending, and heartbeat, are converted to electricity.

Military shoe insoles: Successful experiments have shown powering a GPS tracker with walking force.
There has also been research generating pacemaker auxiliary power using heartbeat pressure.

2) Triboelectric (TENG) — “Electricity generated simply by the friction of clothing against each other.”
This technology literally means static electricity.
It converts the charge generated by the friction of fabrics or arm movements into electricity. A “permanent, battery-free shirt sensor” has been developed by turning the fabric itself into a generator.
Experimental results show that it operates even when washed in a washing machine.

3) Flexible nanogenerator — “A power plant that bends like the body.”
It can be attached to the skin or worn like clothing, and the more it bends, the more electricity it generates.
A multi-mode that simultaneously harvests multiple energy sources, including body temperature, movement, and heartbeat, is also being researched.

📌 Is “permanent operation” truly possible?
Low-power sensors (temperature, pressure, movement, etc.): Close to feasible.
Permanent operation, even with communications like BLE: Still underpowered → Partially feasible with periodic data transmission.
Large devices like smartwatches: “Not possible now, but expected to be partially feasible in the future.”
Self-powered sensors for medical patch sensors, military location sensors, and environmental monitoring wearables are already on the verge of commercialization.

Frankly, this sounds like a rip-off technology, but
with the proliferation of papers, prototypes, and prototypes, and the integration of textile technology,
“battery-free smartwear” is almost a certain future.

Just by wearing it and walking around,
we’re entering an era where sensors will run for life.

It’s crazy technology.
And soon, our bodies will become true “power sources.”

Hey, I just read your post and I gotta ask…
Is it actually real that these sensors can run just from body movement without any battery?
Like… you just walk around and the thing keeps working forever?

Yep, it’s real. Piezo and TENG tech have gotten wild lately.
It used to be “cool lab demo” territory, but now they’re literally weaving this stuff into fabrics.
For low-power sensors, your steps, arm swings, even your heartbeat are enough to keep them running indefinitely.

Damn.
So does that mean we can make smartwatches with no battery at all?
Like… zero charging forever?

lol not yet.
Smartwatches eat way too much power—screens, processors, wireless, all that.
But patch-type health monitors or basic wearable sensors?
Those can run almost permanently on self-generated energy, and they can even transmit data periodically without a battery.

Got it.
So basically: “big power devices = not happening yet,”
but “sensor-only wearables = totally becoming battery-free soon,” right?

Exactly.
We’re pretty much heading into an era where just moving around turns your body into a tiny power plant lol.