Implantable deep brain stimulators have proven their ability to benefit patients suffering from neurological and psychiatric diseases. However, surgery is required every two to three years to swap out the battery that powers these devices. Such intervention might be avoided with technology that uses the patient’s own breathing movements to charge the implant.

The remedy devised by an international research team relies on a nanomaterial-based triboelectric nanogenerator. Static electricity is produced as inhalation and exhalation movements increase pressure on the nanogenerator, creating a current that charges a supercapacitor. The supercapacitor discharges the electricity to power the medical device and stimulate the brain.

Schematic of the energy-harvesting deep brain stimulator. Source: James Rusling et al.

The triboelectric solution was tested in the chest of a simulated pig model containing a pig lung connected to a pump. As the lung is inflated and deflated during inhalation and exhalation, it pushes against the nanogenerator, causing two layers inside the device to rub against each other and produce electricity. The electricity is then transmitted through a thin wire to charge the supercapacitor and powers the deep brain stimulator electronics placed outside the rib cage. The brain stimulator used the electricity stored in the supercapacitor to create pulses 60 times a second, just as it would in a commercial device.

The energy harvesting device described in Cell Reports Physical Science will next be tested in larger animals. Researchers from the University of Connecticut, Tanta University (Egypt), University of Bern (Switzerland), University of California Los Angeles and the National University of Ireland Galway contributed to this development.