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Microfabrication, coil characterization, and hermetic packaging of millimeter-sized free-floating neural probes

Publication ,  Journal Article
Yeon, P; Rajan, SK; Falcone, J; Gonzalez, JL; May, GS; Bellamkonda, RV; Brand, O; Bakir, MS; Ghovanloo, M
Published in: IEEE Sensors Journal
June 15, 2021

This paper presents a new micromachining (MEMS) fabrication, microassembly, and hermetic packaging process for free-floating neural probes (<1 mm3). It offers an intuitive probe assembly and a robust design against mechanical and material failures. A key component of the pushpin neural probe is a 1.3×1.3 mm2 bath-tub shaped micromachined silicon die, which serves as a substrate that supports all passive components in non-plated through-silicon cavities (TSCs) plus four φ 81μm tungsten electrodes embedded in φ100μm non-plated through-silicon holes (TSHs), and a 6-turns bonding wire wound coil (WWC) around the die. The current passive probe prototype houses a 1.2×1.2 mm2 mock-up integrated circuit (IC) in a bath-tub cavity created in the passive micromachined die. The probe is hermetically sealed with a 5μm thick parylene-C film except for the tip of the electrodes, and covered with an additional layer of polydimethylsiloxane (PDMS) for physical protection and reduction of mechanical mismatch with brain tissue. WWCs around the micromachined silicon die are used for power or data transmission and were electrically characterized by theoretical analysis, simulation, and measurements in air and lossy tissue medium. This way, the impact of the inner silicon substrate, packaging, and surrounding tissue on the inductance (Ls) and Q-factor (Qs) of the WWC are studied and related to the resonance frequency (f0) and power transmission efficiency (PTE). The lifetime of the current probe prototypes is estimated by using a customized wireless hermetic failure monitoring tool under an accelerated condition (1 atm, 100% RH, and 80 °C).

Duke Scholars

Published In

IEEE Sensors Journal

DOI

EISSN

1558-1748

ISSN

1530-437X

Publication Date

June 15, 2021

Volume

21

Issue

12

Start / End Page

13837 / 13848

Related Subject Headings

  • Analytical Chemistry
  • 40 Engineering
  • 0913 Mechanical Engineering
  • 0906 Electrical and Electronic Engineering
  • 0205 Optical Physics
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Yeon, P., Rajan, S. K., Falcone, J., Gonzalez, J. L., May, G. S., Bellamkonda, R. V., … Ghovanloo, M. (2021). Microfabrication, coil characterization, and hermetic packaging of millimeter-sized free-floating neural probes. IEEE Sensors Journal, 21(12), 13837–13848. https://doi.org/10.1109/JSEN.2021.3068077
Yeon, P., S. K. Rajan, J. Falcone, J. L. Gonzalez, G. S. May, R. V. Bellamkonda, O. Brand, M. S. Bakir, and M. Ghovanloo. “Microfabrication, coil characterization, and hermetic packaging of millimeter-sized free-floating neural probes.” IEEE Sensors Journal 21, no. 12 (June 15, 2021): 13837–48. https://doi.org/10.1109/JSEN.2021.3068077.
Yeon P, Rajan SK, Falcone J, Gonzalez JL, May GS, Bellamkonda RV, et al. Microfabrication, coil characterization, and hermetic packaging of millimeter-sized free-floating neural probes. IEEE Sensors Journal. 2021 Jun 15;21(12):13837–48.
Yeon, P., et al. “Microfabrication, coil characterization, and hermetic packaging of millimeter-sized free-floating neural probes.” IEEE Sensors Journal, vol. 21, no. 12, June 2021, pp. 13837–48. Scopus, doi:10.1109/JSEN.2021.3068077.
Yeon P, Rajan SK, Falcone J, Gonzalez JL, May GS, Bellamkonda RV, Brand O, Bakir MS, Ghovanloo M. Microfabrication, coil characterization, and hermetic packaging of millimeter-sized free-floating neural probes. IEEE Sensors Journal. 2021 Jun 15;21(12):13837–13848.

Published In

IEEE Sensors Journal

DOI

EISSN

1558-1748

ISSN

1530-437X

Publication Date

June 15, 2021

Volume

21

Issue

12

Start / End Page

13837 / 13848

Related Subject Headings

  • Analytical Chemistry
  • 40 Engineering
  • 0913 Mechanical Engineering
  • 0906 Electrical and Electronic Engineering
  • 0205 Optical Physics