TY - JOUR
T1 - The Microbead
T2 - A 0.009 mm3 Implantable Wireless Neural Stimulator
AU - Khalifa, Adam
AU - Liu, Yuxin
AU - Karimi, Yasha
AU - Wang, Qihong
AU - Eisape, Adebayo
AU - Stanaćević, Milutin
AU - Thakor, Nitish
AU - Bao, Zhenan
AU - Etienne-Cummings, Ralph
N1 - Publisher Copyright:
© 2019 IEEE.
PY - 2019/10
Y1 - 2019/10
N2 - Wirelessly powered implants are increasingly being developed to interface with neurons in the brain. They often rely on microelectrode arrays, which are limited by their ability to cover large cortical surface areas and long-term stability because of their physical size and rigid configuration. Yet some clinical and research applications prioritize a distributed neural interface over one that offers high channel count. One solution to make large scale, fully specifiable, electrical stimulation/recording possible, is to disconnect the electrodes from the base, so that they can be arbitrarily placed freely in the nervous system. In this work, a wirelessly powered stimulating implant is miniaturized using a novel electrode integration technique, and its implanted depth maximized using new optimization design methods for the transmitter and receiver coils. The stimulating device is implemented in a 130 nm CMOS technology with the following characteristics: 300 μm × 300 μm × 80 μm size; optimized two-coil inductive link; and integrated circuit, electrodes and coil. The wireless and stimulation capability of the implant is demonstrated in a conductive medium, as well as in-vivo. To the best of our knowledge, the fabricated free-floating miniaturized implant has the best depth-to-volume ratio making it an excellent tool for minimally-invasive distributed neural interface, and thus could eventually complement or replace the rigid arrays that are currently the state-of-the-art in brain set-ups.
AB - Wirelessly powered implants are increasingly being developed to interface with neurons in the brain. They often rely on microelectrode arrays, which are limited by their ability to cover large cortical surface areas and long-term stability because of their physical size and rigid configuration. Yet some clinical and research applications prioritize a distributed neural interface over one that offers high channel count. One solution to make large scale, fully specifiable, electrical stimulation/recording possible, is to disconnect the electrodes from the base, so that they can be arbitrarily placed freely in the nervous system. In this work, a wirelessly powered stimulating implant is miniaturized using a novel electrode integration technique, and its implanted depth maximized using new optimization design methods for the transmitter and receiver coils. The stimulating device is implemented in a 130 nm CMOS technology with the following characteristics: 300 μm × 300 μm × 80 μm size; optimized two-coil inductive link; and integrated circuit, electrodes and coil. The wireless and stimulation capability of the implant is demonstrated in a conductive medium, as well as in-vivo. To the best of our knowledge, the fabricated free-floating miniaturized implant has the best depth-to-volume ratio making it an excellent tool for minimally-invasive distributed neural interface, and thus could eventually complement or replace the rigid arrays that are currently the state-of-the-art in brain set-ups.
KW - Free-floating implant
KW - microelectrode design
KW - miniaturization
KW - neural stimulation
KW - wireless power transfer
UR - http://www.scopus.com/inward/record.url?scp=85074874779&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85074874779&partnerID=8YFLogxK
U2 - 10.1109/TBCAS.2019.2939014
DO - 10.1109/TBCAS.2019.2939014
M3 - Article
C2 - 31484132
AN - SCOPUS:85074874779
SN - 1932-4545
VL - 13
SP - 971
EP - 985
JO - IEEE Transactions on Biomedical Circuits and Systems
JF - IEEE Transactions on Biomedical Circuits and Systems
IS - 5
M1 - 8822735
ER -