Imec creates innovative neural probe demonstrator
Imec, a leading research and innovation hub in nanoelectronics and digital technologies from Leuven, Belgium, announced at its Imec Technology Forum (ITF) health event, that is has designed and fabricated a demonstrator of a neural probe with unprecedented electrode density within the framework Neuroseeker, a large-scale EU-project. Designed and fabricated in silicon chip technology, the probe is suitable for breakthrough bio-interfaces and implants that are expected to shape the future of neuroscience. With hundreds of electrodes capable of contacting and reading out single neurons, this probe incorporates innovations that point the way to a better understanding of the brain, and ultimately will lead to diagnostic and prosthetic tools to tackle human brain diseases.
Marleen Welkenhuysen, NeuroSeeker project manager at imec, commented: “Our goal was to fabricate a brain probe that would enable a breakthrough in the level of detail by which micro circuits of the brain cortex and also deep brain structures can be studied. Previous probes were severely restricted in the number of signals that could be captured simultaneously which limited their use as a basis for research and therapeutic tools. With this new probe, we demonstrate that it is possible to create powerful electronics that can interface with the brain on the level of small neuronal circuits and even individual neurons.”
35% of all diseases are brain diseases and after the age of 80, there is 90% probability that someone will suffer from a brain disorder. To find a cure for diseases such as Alzheimer’s and Parkinson’s disease, a better insight is needed in how the human brain, which is composed of around 80bn interconnected cells that compute and relay signals chemically and electrically, works. Therefore, tools are needed that align with the size and density of the brain network to measure what is going on in the brain and to influence brain activity. Nanofabrication with silicon chip technology, which is capable of realising ultra-small sensing and activating electrodes at an unprecedented density on a very small surface, is up to the task. Scientists are now learning how to pack the required functionality and density in biocompatible packages for neuroscience applications, following a path similar to Moore’s Law for computer chips. Imec’s new demonstrator neural probe is a stepping stone on that path.
Imec’s NeuroSeeker probe has the size of a chip package and consists of a base chip and protruding needle. The needle is biocompatible and extremely thin (8mm long, 50µm thick, and 100μm wide), to reduce damage to the brain tissue. Along the needle’s shaft hundreds of electrodes are arranged, each a tiny square measuring 20x20µm2. To allow for the dense layout of the electrodes and to be able to read out all electrodes simultaneously, the designers created an innovative time-division multiplexing scheme, which connects 8 electrodes through a single wire with the electronics in the base chip.
Imec’s breakthrough brain probe was fabricated within in the frame of the European FP7 project NeuroSeeker (grant agreement n°600925), a four-year project that was launched in January 2013. The ambitious project was run by an international consortium of leading European and Canadian laboratories with expertise spanning the breath of brain research, from probe technology to theories of information representation.
Caption: Imec’s CMOS-compatible NeuroSeeker high-density neural probe (photo: Imec)