Graphene Brain Implant Turns Thoughts Into Speech

More than 5 million people worldwide suffer annually from aphasia, an extremely invalidating condition in which patients lose the ability to comprehend and formulate language after brain damage or in the course of neurodegenerative disorders. Brain-computer interfaces (BCIs), enabled by forefront technologies and materials, are a promising approach to treat patients with aphasia. The principle of BCIs is to collect neural activity at its source and decode it by means of electrodes implanted directly in the brain. However, neurorehabilitation of higher cognitive functions such as language raises serious issues. The current challenge is to design neural implants that cover sufficiently large areas of the brain to allow for reliable decoding of detailed neuronal activity distributed in various brain regions that are key for language processing.


BrainCom is a FET Proactive project funded by the European Commission with 8.35M€ for the next 5 years. This interdisciplinary initiative involves 10 partners including technologists, engineers, biologists, clinicians, and ethics experts. They aim to develop a new generation of neuroprosthetic cortical devices enabling large-scale recordings and stimulation of cortical activity to study high level cognitive functions. Ultimately, the BraimCom project will seed a novel line of knowledge and technologies aimed at developing the future generation of speech neural prostheses. It will cover different levels of the value chain: from technology and engineering to basic and language neuroscience, and from preclinical research in animals to clinical studies in humans.

This recently funded project is coordinated by ICREA Prof. Jose A. Garrido, Group Leader of the Advanced Electronic Materials and Devices Group at the Institut Català de Nanociència i Nanotecnologia (Catalan Institute of Nanoscience and Nanotechnology – ICN2) and deputy leader of the Biomedical Technologies Work Package presented last year in Barcelona by the Graphene Flagship. The BrainCom Kick-Off meeting is held on January 12-13 at ICN2 and the Universitat Autònoma de Barcelona (UAB).

Recent developments show that it is possible to record cortical signals from a small region of the motor cortex and decode them to allow tetraplegic people to activate a robotic arm to perform everyday life actions. Brain-computer interfaces have also been successfully used to help tetraplegic patients unable to speak to communicate their thoughts by selecting letters on a computer screen using non-invasive electroencephalographic (EEG) recordings. The performance of such technologies can be dramatically increased using more detailed cortical neural information.

BrainCom project proposes a radically new electrocorticography technology taking advantage of unique mechanical and electrical properties of novel nanomaterials such as graphene, 2D materials and organic semiconductors.  The consortium members will fabricate ultra-flexible cortical and intracortical implants, which will be placed right on the surface of the brain, enabling high density recording and stimulation sites over a large area. This approach will allow the parallel stimulation and decoding of cortical activity with unprecedented spatial and temporal resolution.

These technologies will help to advance the basic understanding of cortical speech networks and to develop rehabilitation solutions to restore speech using innovative brain-computer paradigms. The technology innovations developed in the project will also find applications in the study of other high cognitive functions of the brain such as learning and memory, as well as other clinical applications such as epilepsy monitoring.


Cellulose-based Ink For 3D Printing

Empa (Switzerland) researchers have succeeded in developing an environmentally friendly ink for 3D printing based on cellulose nanocrystals. This technology can be used to fabricate microstructures with outstanding mechanical properties, which have promising potential uses in implants and other biomedical applications.

Cellulose, along with lignin and hemicellulose, is one of the main constituents of wood. The biopolymer consists of glucose chains organized in long fibrous structures. In some places the cellulose fibrils exhibit a more ordered structure.

In order to produce 3D microstructured materials for composite applications, for instance, Empa researchers have been using a 3D printing method called “Direct Ink Writing” for the past year. During this process, a viscous substance – the printing ink – is squeezed out of the printing nozzles and deposited onto a surface, pretty much like a pasta machine. Empa researchers Gilberto Siqueira and Tanja Zimmermann from the Laboratory for Applied Wood Materials have now succeeded, together with Jennifer Lewis from Harvard University and André Studart from the ETH Zürich, in developing a new, environmentally friendly 3D printing ink made from cellulose nanocrystals (CNC).
The places with a higher degree of order appear in a more crystalline form. And it is these sections, which we can purify with acid, that we require for our research“, explains Siqueira. The final product is cellulose nanocrystals, tiny rod-like structures that are 120 nanometers long and have a diameter of 6.5 nanometers. And it is these nanocrystals that researchers wanted to use to create a new type of environmentally friendly 3D printing ink.They have now succeeded that  their new inks contain a full 20 percent CNC.

The biggest challenge was in attaining a viscous elastic consistency that could also be squeezed through the 3D printer nozzles“, says Siqueira. The ink must be “thick” enough so that the printed material stays “in shape” before drying or hardening, and doesn’t immediately melt out of shape again.


How To Safely Use Graphene Implants Into Tissues

In the future, our health may be monitored and maintained by tiny sensors and drug dispensers, deployed within the body and made from grapheneone of the strongest, lightest materials in the world. Graphene is composed of a single sheet of carbon atoms, linked together like razor-thin chicken wire, and its properties may be tuned in countless ways, making it a versatile material for tiny, next-generation implants. But graphene is incredibly stiff, whereas biological tissue is soft. Because of this, any power applied to operate a graphene implant could precipitously heat up and fry surrounding cells.

Now, engineers from MIT and Tsinghua University in Beijing have precisely simulated how electrical power may generate heat between a single layer of graphene and a simple cell membrane. While direct contact between the two layers inevitably overheats and kills the cell, the researchers found they could prevent this effect with a very thin, in-between layer of water. By tuning the thickness of this intermediate water layer, the researchers could carefully control the amount of heat transferred between graphene and biological tissue. They also identified the critical power to apply to the graphene layer, without frying the cell membrane.

Co-author Zhao Qin, a research scientist in MIT’s Department of Civil and Environmental Engineering (CEE), says the team’s simulations may help guide the development of graphene implants and their optimal power requirements.


We’ve provided a lot of insight, like what’s the critical power we can accept that will not fry the cell,” Qin says. “But sometimes we might want to intentionally increase the temperature, because for some biomedical applications, we want to kill cells like cancer cells. This work can also be used as guidance [for those efforts.

Qin’s co-authors include Markus Buehler, head of CEE and the McAfee Professor of Engineering, along with Yanlei Wang and Zhiping Xu of Tsinghua University.
The results are published today in the journal Nature Communications.


Brain: Graphene Interacts Safely With Neurons

Researchers from the University of Trieste (Italy) and the University of Cambridge have successfully demonstrated how it is possible to interface graphene – a two-dimensional form of carbon – with neurons, or nerve cells, while maintaining the integrity of these vital cells. The work may be used to build graphene-based electrodes that can safely be implanted in the brain, offering promise for the restoration of sensory functions for amputee or paralysed patients, or for individuals with motor disorders such as epilepsy or Parkinson’s disease. Previously, other groups had shown that it is possible to use treated graphene to interact with neurons. However the signal to noise ratio from this interface was very low. By developing methods of working with untreated graphene, the researchers retained the material’s electrical conductivity, making it a significantly better electrode.

graphene interacts in the brain

For the first time we interfaced graphene to neurons directly,” said Professor Laura Ballerini of the University of Trieste in Italy. “We then tested the ability of neurons to generate electrical signals known to represent brain activities, and found that the neurons retained their neuronal signalling properties unaltered. This is the first functional study of neuronal synaptic activity using uncoated graphene based materials.

The research, published in the journal ACS Nano, was an interdisciplinary collaboration coordinated by the University of Trieste in Italy and the Cambridge Graphene Centre.


How Cellulose Nanogenerators Power Bio-Implants

Implantable electronics that can deliver drugs, monitor vital signs and perform other health-related roles are on the horizon. But finding a way to power them remains a challenge. Now scientists have built a flexible nanogenerator out of cellulose, an abundant natural material, that could potentially harvest energy from the body — its heartbeats, blood flow and other almost imperceptible but constant movements.

implants to monitor vital signsImplantable electronics to monitor vital signs and perform other functions could one day be powered with tiny generators that harvest the body’s energy.

Efforts to convert the energy of motion — from footsteps, ocean waves, wind and other movement sources — are well underway. Many of these developing technologies are designed with the goal of powering everyday gadgets and even buildings. As such, they don’t need to bend and are often made with stiff materials. But to power biomedical devices inside the body, a flexible generator could provide more versatility. So Md. Mehebub Alam and Dipankar Mandal at Jadavpur University in India set out to design one.

The researchers turned to cellulose, the most abundant biopolymer on earth, and mixed it in a simple process with a kind of silicone called polydimethylsiloxane — the stuff of breast implants — and carbon nanotubes. Repeated pressing on the resulting nanogenerator lit up about two dozen LEDs instantly. It also charged capacitors that powered a portable LCD, a calculator and a wrist watch. And because cellulose is non-toxic, the researchers say the device could potentially be implanted in the body and harvest its internal stretches, vibrations and other movements.

The findings appear in the journal ACS Applied Materials & Interfaces.


Brain Injury: How To Monitor Temperature, Pressure

 A new class of small, thin electronic sensors can monitor temperature and pressure within the skullcrucial health parameters after a brain injury or surgery – then melt away when they are no longer needed, eliminating the need for additional surgery to remove the monitors and reducing the risk of infection and hemorrhage.

Nanostructures For Hip and Knee Implants.

Scientists from the Research Center for Advanced Materials (CIMAV) in Mexico look for nanostructures that allow compatibility between metal, human bone tissues. Various scientific projects performed at the Cimav, Unit Monterrey, in the north of Mexico, aimed at one goal: conducting research and apply the knowledge in the development of biomedical implants, since the ones existing in the domestic market come generally from foreign manufacture. Currently this center, part of the National Council for Science and Technology (CONACYT) and located at the Park of Research and Technological Innovation (PIIT), works on the study of novel materials, coating systems and specific properties to use in the manufacture of hip and knee implants, and, in the future, of dental parts. It is the combination of research focused on nanostructured materials with biocompatible and antibacterial properties. In this regard, Ana Maria Arizmendi Morquecho, Cimav scholar, explains that the challenge is to find appropriate measures to improve the compatibility of a metal structure with the chemical composition of bone tissue and human bone’s nanostructures.
ceramic material compatible with the boneWe use a ceramic material which is compatible with the bone, in this case hydroxyapatite, which is used as a matrix and nanoparticles from other materials are used to reinforce it and provide improvements to the bicompatibility, joint wear and mechanical properties” , explains Arizmendi Morquecho
The biocompatibility is the ability of a material to be in contact with a living being without adverse effects, therefore represents one of the most important properties in the manufacture of a biomedical implant. Currently the knee and hip implants are complex systems made of titanium alloy substrates, which require a coating compatible with bone tissue and physiological fluids using nanotechnology; to achieve this intermediate coating deposition techniques of new synthesized materials are used”.