7. Battery-free pacemaker successfully powers the heart
[Image from Rice Integrated Systems and Circuits/Rice University]
The pacemaker, designed by lead researcher Aydin Babakhani, gets its energy wirelessly from radio frequency radiation transmitted from an external battery pack a few centimeters away.
The implantable chip is less than 4 mm wide and uses a receiving antenna, an AC-to-DC rectifier, a power management unit and a pacing activation signal. The circuit board, smaller than a dime, also has a capacitor and switch. Microwaves are transmitted to the switch to power it in the 8–10 gHz of electromagnetic frequency spectrum.
The pacing signals frequency on the pacemaker can be adjusted by increasing and decreasing power to the antenna. The antenna stores the power until it reaches a certain threshold. Once it reaches the threshold, the electrical charge is released and begins to fill again.
A pig’s heart rate was turned from 100 to 172 beats per minute using the chip.
