TY - JOUR
T1 - A Sub-mm3 Ultrasonic Free-Floating Implant for Multi-Mote Neural Recording
AU - Ghanbari, Mohammad Meraj
AU - Piech, David K.
AU - Shen, Konlin
AU - Faraji Alamouti, Sina
AU - Yalcin, Cem
AU - Johnson, Benjamin C.
AU - Carmena, Jose M.
AU - Maharbiz, Michel M.
AU - Muller, Rikky
N1 - Publisher Copyright:
© 2019 IEEE.
PY - 2019/11
Y1 - 2019/11
N2 - A 0.8-mm3-wireless, ultrasonically powered, free-floating neural recording implant is presented. The device is comprised only of a 0.25-mm2 recording integrated circuit (IC) and a single piezoceramic resonator that are used for both power harvesting and data transmission. Uplink data transmission is performed by the analog amplitude modulation of the ultrasound echo. Using a 1.78-MHz main carrier, >35 kb/s/mote equivalent uplink data rate is achieved. A technique to linearize the echo amplitude modulation is introduced, resulting in < 1.2% static nonlinearity of the received signal over a ±10-mV input range. The IC dissipates 37.7 μW, while the neural recording front end consumes 4 μW and achieves a noise floor of 5.3 μ Vrms in a 5-kHz bandwidth. This work improves the sub-mm recording mote depth by >2.5 ×, resulting in the highest measured depth/volume ratio by ∼ 3×. Orthogonal subcarrier modulation enables simultaneous operation of multiple implants, using a single-element ultrasound external transducer. Dual-mote simultaneous power-up and data transmission are demonstrated at a rate of 7 kS/s at the depth of 50 mm.
AB - A 0.8-mm3-wireless, ultrasonically powered, free-floating neural recording implant is presented. The device is comprised only of a 0.25-mm2 recording integrated circuit (IC) and a single piezoceramic resonator that are used for both power harvesting and data transmission. Uplink data transmission is performed by the analog amplitude modulation of the ultrasound echo. Using a 1.78-MHz main carrier, >35 kb/s/mote equivalent uplink data rate is achieved. A technique to linearize the echo amplitude modulation is introduced, resulting in < 1.2% static nonlinearity of the received signal over a ±10-mV input range. The IC dissipates 37.7 μW, while the neural recording front end consumes 4 μW and achieves a noise floor of 5.3 μ Vrms in a 5-kHz bandwidth. This work improves the sub-mm recording mote depth by >2.5 ×, resulting in the highest measured depth/volume ratio by ∼ 3×. Orthogonal subcarrier modulation enables simultaneous operation of multiple implants, using a single-element ultrasound external transducer. Dual-mote simultaneous power-up and data transmission are demonstrated at a rate of 7 kS/s at the depth of 50 mm.
KW - Echo modulation
KW - energy harvesting
KW - implantable biomedical devices
KW - linearization
KW - neural recording
KW - nonlinear acoustics
KW - piezoelectric
KW - ultrasound
UR - http://www.scopus.com/inward/record.url?scp=85074343124&partnerID=8YFLogxK
UR - https://scholarworks.boisestate.edu/electrical_facpubs/478
U2 - 10.1109/JSSC.2019.2936303
DO - 10.1109/JSSC.2019.2936303
M3 - Article
SN - 0018-9200
VL - 54
SP - 3017
EP - 3030
JO - IEEE Journal of Solid-State Circuits
JF - IEEE Journal of Solid-State Circuits
IS - 11
M1 - 8848490
ER -