Graphene and Magnetics On the Brain: Researching Bioelectronic Brain Implants

June 19, 2021 by Nicholas St. John

As the gap between electronics and biology grows smaller, more devices are being researched. Recently, a focus has been on bioelectronics, namely implants for your brain.

Lately, there has been a boom of interest in the research field of bioelectronics, namely those of implants. Since the brain has always been a point of interest for researchers. As our technology finds capabilities and applications in biological systems, the time to look to unlock the brain's secrets could be now.


A high-level framework for messing biology and electronics.

A high-level framework for messing biology and electronics. Image used courtesy of Teo et al


Another key insight to this flood of interest is how studying the brain can be done in tandem with finding therapeutic solutions for brain disorders such as Parkinson's disease with electrical hardware.

This article will discuss hardware that is being developed for brain interfaces, along with the prospect of the closing gap between the world of biology and electrical engineering. 


Using Graphene in Neural Implants

One company attempting to find a solution to brain disorders and diseases through technology is a spin-off company of Graphene Flagship called INBRAIN Neuroelectronics

INBRAIN is developing graphene-based neural implants that can deliver personalized therapies to patients suffering from neurological disorders such as epilepsy, Parkinson's, and many others. 

The key divider between INBRAIN's solution and other neural implants is that it uses graphene, while most competitors' brain interfaces are based on metals, usually platinum and iridium. Unfortunately, these metals can cause limitations in size and signal resolution, resulting in a 50% rejection rate in patients. 


Surface area of INBRAIN's prototype.

The surface area of INBRAIN's prototype. Image used courtesy of Garcia-Cortadella et al


Unlike those metals, graphene does not have these same limitations, as it can be manufactured at the nanoscale, with future aspects of eventually reaching a single-neuron resolution. Also, graphene is biocompatible, lightweight, and highly conductive, making it much safer to implant and charged wirelessly. 

These graphene implants then use AI to learn the brain's functionality, allowing it to send personalized adaptive responses to the brain. While this can happen autonomously, the implant could permit remote monitoring and data processing.

Another novel aspect of INBRAIN's design is its ability to measure brain waves in a wide frequency band, from extremely low (~10 Hz) to high frequencies. This extremely low region has eluded sensors in the past again because most previous implants used incompatible metals. 


The circuit schematic for INBRAIN's device.

The circuit schematic for INBRAIN's device. Image used courtesy of Garcia-Cortadella et al


According to Graphene Flagship, this low-frequency brain activity tends to dictate the behavior of the high frequencies, and thus reading this band can decode the brain states of the patient. In addition, this implant saw zero compatibility issues when tested in rats, as the high and low-frequency activity correlated very well with one another. 

After achieving positive test results, the team looks for commercial applications to get this implant out to the world.

Though using graphene in bioelectronics is just one out of many ideas being researched, another focuses on the role of magnets in bioelectronics.


Rice University's MagNI: Charging Implants with Magnets

Researchers from Rice University are also innovating in this space, with an engineering team designing a MagNI (magnetoelectric neural implant). 


The MagNI from Rice University.

The MagNI from Rice University. Image used courtesy of Rice University


This device allows for charging and programming of the implant via a magnetic field produced by a wearable belt. It uses magnetoelectric transducers to do this, as it can harvest alternating magnetic fields outside of the body since the body does not absorb or get heated from magnetic fields. 

The MagNI allows programmed electrical stimulation of neurons that can help patients with neurological disorders. The device is highly compact, requiring only three components that sit on a flexible polyimide substrate, a 2x4 mm magnetoelectric film that converts the magnetic field to an electric field, a CMOS chip, and a capacitor for temporary energy storage. 

Currently, the research team is trying to achieve a bidirectional flow of energy and information within the device, rather than how, at the moment, the energy can only flow into the device.

Despite the setbacks in developing this bioelectronic device, the world of biology and electronics is steadily shrinking as more advancements and research come to fruition. 


Bridging the Gap?

The interdisciplinary interests of these applications are making their way into the classrooms as well, as Harvard's John A. Paulson School of Engineering and Applied Sciences has created a new course, Introduction to Bioelectronics (BE 129). 

According to Harvard, this course introduces the challenges and exciting applications that this field offers and preps the students based on the wide breadth of knowledge needed to work in this space effectively. 

While the bioelectronics field began in the mid-18th century, questions like the brain's functionality remain a mystery. This class aims to train the next generation to solve these long-awaited questions, namely with technology.

While the bioelectronics field began in the mid-18th century, questions like the brain's functionality remain a mystery. This class aims to train the next generation to solve these long-awaited questions, namely with technology.


Final Thoughts

Overall, bioelectronics is a field ripe with opportunities for researchers and engineers alike. Although there is still much to learn and much to unlock within our bodies, and these problems continue to be solved, more healing methods and helping others with electronics become possible.




Interested in other bioelectronic news? Read more in the articles down below. 

The Future of Vision Looks Bright With Advances in Prosthetic Retinas

Purdue Researchers Creates Wireless, Implantable Transmitter to Power Future Biomedical Devices

Making Safer Implantable Medical Sensors: The Benefits and Challenges of Biodegradable Sensors