The ability to deliver flexible biosensors through the toughest membranes of the central and peripheral nervous system is an important challenge in neuroscience and neural engineering. Bioelectronic devices implanted through dura mater and thick epineurium would ideally create minimal compression and acute damage as they reach the neurons of interest. We demonstrate that a three-dimensional diamond shuttle can be easily made with a vertical support to deliver ultra-compliant polymer microelectrodes (4.5-µm thick) through dura mater and thick epineurium. The diamond shuttle has 54% less cross-sectional area than an equivalently stiff silicon shuttle, which we simulated will result in a 37% reduction in blood vessel damage. We also discovered that higher frequency oscillation of the shuttle (200 Hz) significantly reduced tissue compression regardless of the insertion speed, while slow speeds also independently reduced tissue compression. Insertion and recording performance are demonstrated in rat and feline models, but the large design space of these tools are suitable for research in a variety of animal models and nervous system targets.
Bibliographical noteFunding Information:
The authors thank the staff of the Lurie Nanofabrication Facility for their tool support and technical advice when needed. We thank Paras Patel for his help in PEDOT-pTS coating. We also thank Ahmad Jiman, Zhonghua Aileen Ouyang, and Lauren Zimmerman for their help in 3D printing materials for and/or data collection in feline experiments. This work was supported in part by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health (R21EB020811, and SPARC program Awards U18EB021760, OT2OD024907, and OT2OD023873), Kavli Foundation funding, and Seed Funding for Innovative Projects in Neuroscience from the University of Michigan Brain Initiative Working Group (MiBrain). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the University of Michigan.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Materials Science (miscellaneous)
- Condensed Matter Physics
- Industrial and Manufacturing Engineering
- Electrical and Electronic Engineering