Researchers at Toyohashi University of Technology in Japan have fabricated an implanted wireless power transmission (WPT) device that delivers power to an implanted neural interface system, such as a brain-computer interface (BCI) device. This implant avoids risk of infections through skull opening and leakage of cerebrospinal fluid, and allows for free-moving subjects and more flexible uses of brain-computer interfaces
Described in an open-access paper in Sensors journal, the system avoids having to connect an implanted device to an external power source via wires through a hole in the skull, which can cause infections through the opening and risk of infection and leakage of the cerebrospinal fluid during long-term measurement. The system also allows for free-moving subjects, allowing for more natural behavior in experiments.
The researchers used a wafer-level packaging technique to integrate a silicon large-scale integration (LSI) chip in a thin (5 micrometers), flexible parylene film, using flip-chip (face-down) bonding to the film. The system includes a thin-film antenna and a rectifier to convert a radio-frequency signal to DC voltage (similar to how an RFID chip works). The entire system measures 27 mm × 5 mm, and the flexible film can conform to the surface of the brain.
The researchers plan to integrate additional functions, including amplifiers, analog-to-digital converters, signal processors, and a radio frequency circuit for transmitting (and receiving) data.
Such a system could perform some of the functions of the Braingate system, which allows paralyzed patients to communicate (see “People with paralysis control robotic arms using brain-computer interface“).
This work is partially supported by Grants-in-Aid for Scientific Research, Young Scientists, and the Japan Society for the Promotion of Science.