Nanoenabled Direct Contact Interfacing of Syringe-Injectable Mesh Electronics

Jung Min Lee, Guosong Hong, Dingchang Lin, Thomas G. Schuhmann, Andrew T. Sullivan, Robert D. Viveros, Hong Gyu Park, Charles M. Lieber

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

Polymer-based electronics with low bending stiffnesses and high flexibility, including recently reported macroporous syringe-injectable mesh electronics, have shown substantial promise for chronic studies of neural circuitry in the brains of live animals. A central challenge for exploiting these highly flexible materials for in vivo studies has centered on the development of efficient input/output (I/O) connections to an external interface with high yield, low bonding resistance, and long-term stability. Here we report a new paradigm applied to the challenging case of injectable mesh electronics that exploits the high flexibility of nanoscale thickness two-sided metal I/O pads that can deform and contact standard interface cables in high yield with long-term electrical stability. First, we describe the design and facile fabrication of two-sided metal I/O pads that allow for contact without regard to probe orientation. Second, systematic studies of the contact resistance as a function of I/O pad design and mechanical properties demonstrate the key role of the I/O pad bending stiffness in achieving low-resistance stable contacts. Additionally, computational studies provide design rules for achieving high-yield multiplexed contact interfacing in the case of angular misalignment such that adjacent channels are not shorted. Third, the in vitro measurement of 32-channel mesh electronics probes bonded to interface cables using the direct contact method shows a reproducibly high yield of electrical connectivity. Finally, in vivo experiments with 32-channel mesh electronics probes implanted in live mice demonstrate the chronic stability of the direct contact interface, enabling consistent tracking of single-unit neural activity over at least 2 months without a loss of channel recording. The direct contact interfacing methodology paves the way for scalable long-term connections of multiplexed mesh electronics neural probes for neural recording and modulation and moreover could be used to facilitate a scalable interconnection of other flexible electronics in biological studies and therapeutic applications.

Original languageEnglish
Pages (from-to)5818-5826
Number of pages9
JournalNano Letters
Volume19
Issue number8
DOIs
Publication statusPublished - 2019 Aug 14

Keywords

  • Double-sided metal input/output
  • biocompatible neural probes
  • chronic neural interface
  • flexible electronics
  • flexible input/output
  • multiplexed electrophysiology

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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