Optical Interconnect for High-Density Neural Signals

Razi-ul Haque | 18-ERD-042

Project Overview

The aim of this project was to develop and demonstrate a first-of-its kind, implantable, high-density neural interface capability to address fundamental neuroscience challenges identified by the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative, a research initiative supported by multiple government agencies. Addressing this challenge, we proposed a novel approach to convert the standard electrical signals typically recorded from the brain and convert them into an optical signal, improving data transmission fidelity and bandwidth, and reducing physical size. An optically-transparent, hermetically-sealed micro package was proposed, using microfabrication techniques and advanced laser-welding techniques. Through this program, we developed the fundamental basic building blocks to achieve this vision, including (1) a demonstration of new optical materials, such as microfabricated and additively manufactured polymers, to waveguide light; (2) a new glass laser-welding process; (3) a new waveguiding technique embedded within glass; and (4) a demonstration of emulated data transmission using chip-based laser diodes through an optical path with custom-designed components. Technologies developed in this project will have an immediate and profound impact on neuroscience by providing quick, easy access to much more data than is possible today, enabling behavioral neuroscientists to perform unprecedented, complex studies in ambulatory animals expected to lead to new insights on the underlying neural circuitry of the brain.

Mission Impact

The technologies developed in this project will support research related to the underlying neural circuitry of the brain. Beyond these types of neuroscience applications, we envision mission-relevant applications of this technology, such as the ability to develop interconnected, implantable sensors that can monitor other physiological signals to develop countermeasures against chemical/biological weapons, a Lawrence Livermore National Laboratory mission research challenge area. Computation efforts can also benefit by microscale optical links that are simply "plug-and-play" but much smaller than state-of-the-art solutions. Thus, our research also supports the Laboratory's core competencies in bioscience and bioengineering; lasers and optical science and technology; and advanced materials and manufacturing.

Publications, Presentations, and Patents

Kampasi, K. et al. 2020a. "Design and Microfabrication Strategies for Thin-Film, Flexible Optical Neural Implant" International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), Montreal, QC, Canada, July 2020. LLNL-CONF-804102

——— 2020b. "POEMS (Polymeric Opto-Electro-Mechanical Systems) for Advanced Neural Interfaces", Materials Letters, doi: 10.1016/j.matlet.2020.129015. LLNL-JRNL-810279

Patra, S. et al. 2018a. "All Optical Electrode Interface for Bioengineering Application." U.S. Patent Application 16/591,792.

——— 2018b. "Opto-Electronic Interface for High Density Electrode." U.S. Patent Application 16/591,821.

——— 2019. "Hybrid Optical Multichip Module Platform." U.S. Patent Application 16/707,764.

Sahoo, P. K. et al. 2020, "Dynamic modelling for predicting temperature evolution and modification during fs-laser welding of borofloat glass" Conference on Lasers and Electro-Optics, Washington, D.C., May 2020. doi:10.1364/CLEO_AT.2020.ATu3K.2 LLNL-CONF-798618