ASCENT: Ultra-high Throughput Neural Recording using Flexible, Polymer-based Shanks as Terahertz Dielectric Waveguides

ASCENT：使用柔性聚合物柄作为太赫兹介电波导进行超高吞吐量神经记录

• 批准号: 2133138
• 负责人: Constantine Sideris
• 金额: $ 150万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-15 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2133138&HistoricalAwards=false
• 关键词: ASCENT; Ultra; Throughput; Neural; Recording

Brain Machine Interfaces (BMI) are used to record the electrical signals of the neurons in the brain and gain insights into the complex processes occurring in the brain and nervous system. This understanding is crucial to repair or augment cognitive and/or sensory and motor functions, which might be necessary, e.g., due to damage to the brain sustained by injuries or diseases. Traditional recording by electroencephalography (EEG) or functional magnetic resonance imaging (MRI) is too crude, cumbersome, and slow for many of these tasks; therefore, BMIs with implanted microelectrodes need to be used. However, state of the art implantable electrode arrays (IEAs) made from rigid silicon not only have short lifetimes but can also damage the brain tissue and cause scar formation. Recently, IEAs have been developed using flexible polymer-based shanks which minimize tissue damage during implantation, significantly increasing safety and paving the way towards long-term recording. Unfortunately, the number of electrodes, and thus the amount of data that can be recorded, is very limited. To pave the way for new basic science discoveries in neuroscience and the development of new, safe BMIs to treat individuals with brain injury or disease, this project introduces a new, completely wireless approach that has virtually unlimited data bandwidth for communicating data outside of the brain and enables safe, long term brain recording via biocompatible, flexible polymer electrodes. The system is expected to have a huge impact on advancing the state-of-the-art in IEA technology by enabling, for the first time ever, safe and high-density neural recording over multiple year-long durations. The technological advances in hybrid silicon-polymer fabrication and chip-to-chip communication via polymer waveguides will also hold scientific and practical application value in their own right.A major problem facing brain machine interfaces is achieving both high data throughput and long lifespans when recording neural activity. To overcome current limitations on recording density and lifetime, this project will develop and prototype a new implantable electrode array technology that combines active silicon complementary metal oxide semiconductor (CMOS)-based electrodes with a biocompatible polymer shank. The Parylene C polymer is flexible and can be microfabricated such that multiple custom, fully wireless CMOS neural recording chiplets can be arranged along the length of each shank. The polymer shank, acting as a dielectric waveguide, will carry both red light and Terahertz (THz) radio-frequency energy from outside the brain to the chiplets for power harvesting and backscatter data communication, respectively, obviating the need for wires. On-chip photodiodes will rectify the incident optical light for powering each chip, and on-chip THz antennas will be used to modulate the locally recorded and amplified neuronal data onto the THz carrier signal inside the polymer shank via backscatter communication. Extensive modeling will be done of the electromagnetic characteristics of the polymer shank waveguides at both optical and THz wavelengths in order to optimize the shank cross-section and design of the THz surface coupling antennas for maximizing system efficiency and communication bandwidth. Each chiplet will contain a dense neural recording electrode array with active amplification, filtering, and spike detection circuitry for recording, digitizing, and compressing neuronal data before modulating it on the THz carrier signal and sending it to the base via the polymer shank waveguide. Importantly, this paradigm achieves a completely wireless system that maximizes the number of neural recording sites and contributes a new hybrid silicon-polymer architecture capable of efficient, high-bandwidth quasi-optical chip-to-chip communication.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

脑机界面（BMI）用于记录大脑中神经元的电信号，并洞悉大脑和神经系统中发生的复杂过程。这种理解对于修复或增强认知和/或感觉和运动功能至关重要，例如，由于受伤或疾病遭受的大脑损害，可能是必要的。脑电图（EEG）或功能性磁共振成像（MRI）的传统记录过于粗糙，麻烦且缓慢。因此，需要使用带有微电极的BMI。但是，由刚性硅制成的最先进的可植入电极阵列（IEAS）不仅寿命很短，而且还会损害脑组织并导致疤痕形成。最近，使用基于柔性聚合物的小腿开发了IEA，从而最大程度地减少了植入过程中的组织损伤，显着提高了安全性并为长期记录铺平了道路。不幸的是，电极的数量以及可以记录的数据量非常有限。为了为神经科学的新基础科学发现铺平道路，并开发了新的，安全的BMI来治疗脑损伤或疾病的个体，该项目引入了一种新的，完全无线的方法，该方法实际上具有无限的数据包裹，以在脑外部传达数据，并可以通过生物兼容，柔性的，可通过生物相容性的，柔性的聚合物来启用安全，长期的脑部记录。预计该系统将通过在长达一年的时间内首次实现安全且高密度的神经记录，对IEA技术的最先进技术产生巨大影响。混合硅聚合物制造和通过聚合物波导的芯片到芯片交流的技术进步还将在其自身的权利中具有科学和实用的应用价值。在记录神经活动时，脑机界面面临的主要问题既可以实现高数据吞吐量，又可以实现较长的寿命。为了克服当前对记录密度和寿命的局限性，该项目将开发并原型一种新的可植入电极阵列技术，该电极阵列技术结合了活性硅互补金属氧化物半导体（CMOS）基于生物相容性的聚合物柄。 Parylene C聚合物具有柔韧性，可以进行微观生体，以便可以沿着每个小腿的长度排列多个自定义，完全无线的CMOS神经记录chiplets。充当介电波导的聚合物柄将分别从大脑外部到芯片，分别携带红光和Terahertz（THZ）射频射频能量，分别以进行功率收集和反向散射数据通信，从而避免了电线的需求。片上光二极管将纠正入射光学光，以供电每个芯片，并且片上THZ天线将用于通过反向散射通信来调节聚合物柄内部的THZ载体信号上的局部记录并放大神经元数据。为了优化THZ表面耦合天线的柄横截面和设计，将对聚合物柄波导的电磁特性进行广泛的建模，以最大程度地提高系统效率和通信带宽。每个花栗鼠都将包含一个密集的神经记录电极阵列，并具有主动放大，过滤和尖峰检测电路，以记录，数字化和压缩神经元数据，然后将其调节在THZ载体信号上并通过聚合物尚克波吉德（Polymer Shank Waveguide）进行调节并将其发送到底座。重要的是，该范式实现了一个完全无线的系统，可最大程度地提高神经记录站点的数量，并为能够有效的高带宽准积分芯片到芯片交流的新型混合硅聚合物体系结构提供了奖励。该奖项奖励NSF的法定任务，反映了通过评估的构成群体的支持者，该奖项已被视为众所周知的构成者的宗旨。