Funding agency
National Science FoundationAward number
CBET-1555720Dates
September 1, 2015-August 31, 2018Description
For many decades, the interaction between humans and machines has been restricted to the exchange of visual, auditory and tactile information. A conceptual analysis of the existing human-machine interfaces (HMI) reveals that the amount of useful information that can be exchanged between humans and machines is not limited by the capabilities of the human brain or those of the machine processor, but by the interfaces between them. To overcome such limitation, many brain-machine interfaces (BMI) have been developed within the last years. For example, electroencephalogram (EEG) signals have been successfully utilized to control machines in a non-invasive way and with high temporal resolution. However, EEG-based BMIs cannot be utilized to read the activity from a single neuron at a time and are vulnerable to electrical artifact sources. In parallel to the development of the aforementioned approaches, the field of optogenetics, i.e., the use of light to interact with genetically modified neurons in the brain, has experienced a major revolution in the last decade. Optical neural stimulation is considered to be more beneficial than electrical neural stimulation, because it permits activation or inhibition of specific types of neurons with sub-millisecond temporal precision and eliminates electrical artifacts. However, existing optical devices used for BMIs are highly invasive, difficult to interface with single neurons, and, ultimately, not suitable for permanent BMIs.
The objective of the proposed project is to prove the feasibility of novel nanophotonic brain-machine interfaces based on the use of a distributed network of nano-devices to monitor and control the neuronal activity in the brain. The fundamental idea is to replace existing micro-led arrays and micro- photodetector arrays by a network of coordinated nano-devices, which are able to optically excite individual neurons and measure their activity. The benefits of this approach are several. First, the very small size of optical nano-antennas, below one micrometer in the largest dimension, enables the possibility to measure the neuronal activity in a single neuron with very high accuracy. In addition, the total size of each individual nano-device is expectedly below several tens of cubic micrometers, thus minimizing the invasiveness of this approach. Moreover, by operating at optical frequencies, a very high temporal resolution is possible, which can enable the measurement of high-frequency time-transients in the neuronal activity. Within this long-term goal, the focus of this two-year EAGER project is on establishing the foundations of distributed neuronal ac- tivity monitoring with cooperative nano-devices for next-generation nanophotonic brain-machine interfaces. Contributions will be made along the following three main thrusts: i) Design of optical nano-antennas for efficient detection of visible electromagnetic radiation generated by neuronal activity; ii) Development of a neuronal platform for experimental optogenetics; and, iii) System-level design guidelines for nanophotonic BMIs.
The project is expected to pave the way for the development of high-throughput nanopho- tonic BMIs. The proposed approach can significantly simplify and reduce the cost of existing single-neuron monitoring and control platforms, with increased spatial and temporal resolutions. Nano-photonic BMIs have the potential to significantly improve the quality of life of people with disabilities, by providing them a new way to bidirectionally interact with machines and, ultimately, their environment. In particular, the creation of a “direct-path” between the brain and external machines can help to overcome the limitations of people with general or aging-related disabilities and restore human functional abilities and even cognition. For example, neural signals from the brain could be utilized to directly control a computer or even an exoskeleton. Simi- larly, the proposed technology could help to develop transformative treatments for many developmental- and aging-related diseases, such as Alzheimer’s disease or Schizophrenia, whose origin lies at communication problems between consecutive neurons. An interdisciplinary team with complementary expertise has been created to pursue the proposed research plan, and several graduate and undergraduate students as well as one postdoctoral fellow will be involved in the completion of the proposed work.