ChroMOS · Toward monolithic CMOS based neural probes for stable chronic recording and brain machine interfaces
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2020-11-01 → 2022-10-31
- EU contribution
- €183,473
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Toward monolithic CMOS based neural probes for stable chronic recording and brain machine interfaces
The brain influences all aspects of our life, is the most complex organ of the body and is composed by billions of cells, mainly neurons and glia. Neurological conditions are the second leading cause of death worldwide and the leading cause of Disability Adjust Life Years, accordingly to World Health Organization. It’s key to better understand and monitor the brain in order to prevent and cure brain related diseases, such as stroke, dementia, epilepsy, depression, drug addiction, and Parkinson and Alzheimer disease. The introduction of high-density implantable neural probes based on complementary metal–oxide semiconductor (CMOS) technology, such as the SiNAPS probes developed in our lab, is a big step forward in neuroscience. These new probes provide simultaneous access to thousands of single neurons in different brain circuits, introducing hundreds of closely spaced microelectrodes into the substrate for recording extracellular bioelectrical signals. However, when a device is implanted in the brain, it triggers tissue-reactions to protect the brain from the device, called foreign body response (FBR). Such FBR leads to device loss of recording quality over time and eventually to its complete failure. An emerging hypothesis to minimize tissue-reactions and improve chronic stability of implantable probes consists in downscaling the cross-sectional sizes of their shafts (implanted part) as well as the overall system size. Downscaling the size of conventional implantable probes is at the cost of a drastically reduced number of recording sites due to technological limitations, which leads to limited information retrieved from the brain. The ChroMOS project explored the key advantages of monolithic CMOS-based neural probes together with the optimization of circuits, materials and microfabrication processes to reduce the size of the probe to micro-wire like dimensions (≈ 30 µm diameter) while maintaining a high number of recording sites.
Data: CORDIS, © European Union
Project objective
The recent advent of active high-density implantable neural probes based on CMOS technology is a big leap forward in neuroscience. Unprecedentedly, these new probes provide simultaneous access to several thousands of single-neurons in different brain circuits. Although realized with different circuit’s architectures, such devices combine the use of standard CMOS and MEMS technologies to realize monolithic active dense probes that integrate into the same substrate hundreds of closely spaced microelectrodes together with electronic circuits for recording extracellular bioelectrical signals. However, despite their unique value, current CMOS-probes are not yet adapted for chronically stable implants and this is a major drawback both for neuroscience research as well as for growing potential clinical applications in fields such as brain-machine-interfaces or neuroprosthetics.An emerging hypothesis to minimize tissue-reactions and improve chronic stability of implantable probes consists in downscaling the cross-sectional sizes of their shafts as well as the overall system size. This fellowship proposes a deep study of this hypothesis by exploiting key advantages of monolithic CMOS based neural probes together with the optimization of circuits, materials and microfabrication processes. I will exploit my background in MEMs technologies and acquire new expertise in neuroscience to evaluate solutions for reducing CMOS shanks dimensions (20-80 µm width, 15-30 µm thick), strategies to improve tissue-materials interfaces, and to assess the effects of these features on brain tissue responses and recording performances. This will lead to ChroMOS probes with a very thin and uniform width (tens of microns) through all the shaft, and with electrode densities up to 1000 sites/mm2. This can lead to remarkably stable probe’s implants with large-scale single-neuron recording capabilities, far behind current technologies.
Original text from CORDIS.
Participants
- FONDAZIONE ISTITUTO ITALIANO DI TECNOLOGIA · GenovaCoordinatorItaly
Links
Data: CORDIS, © European Union