A smartphone-controlled neural implant will advance neuroscience

Researchers from the KAIST School of Electrical Engineering have developed a soft neural implant that can be wirelessly controlled using a smartphone and whose payload (medications and light pulses) can be adjusted indefinitely.

By using interchangeable Lego-like drug cartridges and a low-energy Bluetooth data connection, the implant can target specific neurons that use medication and light over a long period of time. The study, led by Professor Jae-Woong Jeong, was published in the journal Nature Biomedical Engineering.

“This is the new fruit of advanced electronic design and powerful micro and nanotubes,” explained Professor Jeong. “We are interested in further developing this technology to make a brain implant for clinical applications.”

It is claimed that this technology significantly overshadows conventional methods used by neuroscientists, which typically include rigid metal tubes and optical fibers for drug and light delivery. In addition to restricting the subject’s movement due to cumbersome equipment, their relatively rigid structure over time causes lesions in the soft tissue of the brain, making them unsuitable for long-term implantation. Although some efforts have been made to partially mitigate the negative tissue response by including soft probes and wireless platforms, previous solutions have been limited by the inability to deliver drugs over an extended period of time as well as by their cumbersome and complex control settings.

In order to achieve chronic wireless drug delivery, scientists had to address the critical challenge of drug exhaustion and evaporation. To combat this, the researchers invented a neural device with a replaceable drug container, which could allow neurologists to study the same brain circuits for several months without worrying about running out of drugs.

These “plug-n-play” drug cartridges were assembled into a brain implant for mice with a soft and ultra-thin probe (human hair thickness), consisting of microfluidic channels and tiny LEDs (smaller than a grain of salt), for unlimited drug doses and light delivery.

Controlled by a sleek and simple user interface on a smartphone, neuroscientists can easily initiate any specific combination or precise sequencing of light and drug delivery in any implanted target animal, without having to physically reside within the laboratory. Using these wireless neural devices, researchers can also easily set up fully automated animal studies where the behavior of one animal could affect other animals by initiating light and / or drug delivery.

“The wireless neural device provides chronic chemical and optical neuromodulation that has never been achieved before,” said lead author Raza Qazi, a researcher at KAIST and the University of Colorado Boulder. This work was supported by scholarships from the National Research Foundation of Korea, the US National Institutes of Health, the National Institute on Drug Abuse, and the Mallinckrodt Professorship.