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 (HMIs) reveals that the amount of useful information that they can transfer is generally not limited by the capabilities of the human brain or those of the machine processor, but by the interfaces between them, such as the sensor organs that are required to handle visual, auditory and tactile information. This is especially true for people with developmental- and aging-related disabilities, whose sensor organs or musculoskeletal system further limit the functionality of traditional HMIs. To overcome such limitation, several brain-machine interfaces (BMIs), which establish a direct path between the brain and a remote machine, have been proposed in the last decade. 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 individual neurons, but only their collective response. Similarly, optogenetics-based BMIs, which rely on the use of light to interact with genetically modified neurons in the brain, can be utilized to more accurately read or control the neuronal activity in the brain. However, existing optical devices used for BMIs are highly invasive and difficult to interface with single neurons.
In this project, novel nanophotonic BMIs will be developed by leveraging the state of the art in nanophotonics, nanoelectronics and wireless communications. The proposed technology relies on the use of a distributed network of nano-devices to monitor and control the neuronal activity of the human brain with very high spatial and temporal accuracy and in a minimally invasive way. This technology is expected to significantly change the way in which humans interact with machines and can significantly improve the quality of life of people with disabilities, by providing them a transformative way to interact with the environment and restoring functional abilities as well as cognition capabilities.
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 activity 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.
In terms of broader impact, the project is expected to pave the way for the development of high-throughput nanophotonic 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. Nanophotonic 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. Similarly, 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.
