Tag Archives: brain-machine interface

US National Academies Sept. 22-23, 2022 workshop on techno, legal & ethical issues of brain-machine interfaces (BMIs)

If you’ve been longing for an opportunity to discover more and to engage in discussion about brain-machine interfaces (BMIs) and their legal, technical, and ethical issues, an opportunity is just a day away. From a September 20, 2022 (US) National Academies of Sciences, Engineering, and Medicine (NAS/NASEM or National Academies) notice (received via email),

Sept. 22-23 [2022] Workshop Explores Technical, Legal, Ethical Issues Raised by Brain-Machine Interfaces [official title: Brain-Machine and Related Neural Interface Technologies: Scientific, Technical, Ethical, and Regulatory Issues – A Workshop]

Technological developments and advances in understanding of the human brain have led to the development of new Brain-Machine Interface technologies. These include technologies that “read” the brain to record brain activity and decode its meaning, and those that “write” to the brain to manipulate activity in specific brain regions. Right now, most of these interface technologies are medical devices placed inside the brain or other parts of the nervous system – for example, devices that use deep brain stimulation to modulate the tremors of Parkinson’s disease.

But tech companies are developing mass-market wearable devices that focus on understanding emotional states or intended movements, such as devices used to detect fatigue, boost alertness, or enable thoughts to control gaming and other digital-mechanical systems. Such applications raise ethical and legal issues, including risks that thoughts or mood might be accessed or manipulated by companies, governments, or others; risks to privacy; and risks related to a widening of social inequalities.

A virtual workshop [emphasis mine] hosted by the National Academies of Sciences, Engineering, and Medicine on Sept. 22-23 [2022] will explore the present and future of these technologies and the ethical, legal, and regulatory issues they raise.

The workshop will run from 12:15 p.m. to 4:25 p.m. ET on Sept. 22 and from noon to 4:30 p.m. ET on Sept. 23. View agenda and register.

For those who might want a peak at the agenda before downloading it, I have listed the titles for the sessions (from my downloaded Agenda, Note: I’ve reformatted the information; there are no breaks, discussion periods, or Q&As included),

Sept. 22, 2022 Draft Agenda

12: 30 pm ET Brain-Machine and Related Neural Interface Technologies: The State and Limitations of the Technology

2:30 pm ET Brain-Machine and Related Neural Interface Technologies: Reading and Writing the Brain for Movement

Sept. 23, 2022 Draft Agenda

12:05 pm ET Brain-Machine and Related Neural Interface Technologies: Reading and Writing the Brain for Mood and Affect

2:05 pm ET Brain-Machine and Related Neural Interface Technologies: Reading and Writing the Brain for Thought, Communication, and Memory

4:00 pm ET Concluding Thoughts from Workshop Planning Committee

Regarding terminology, there’s brain-machine interface (BMI), which I think is a more generic term that includes: brain-computer interface (BCI), neural interface and/or neural implant. There are other terms as well, including this one in the title of my September 17, 2020 posting, “Turning brain-controlled wireless electronic prostheses [emphasis mine] into reality plus some ethical points.” I have a more recent April 5, 2022 posting, which is a very deep dive, “Going blind when your neural implant company flirts with bankruptcy (long read).” As you can see, various social issues associated with these devices have been of interest to me.

I’m not sure quite what to make of the session titles. There doesn’t seem to be all that much emphasis on ethical and legal issues but perhaps that’s the role the various speakers will play.

Better recording with flexible backing on a brain-computer interface (BCI)

This work has already been patented, from a March 15, 2022 news item on ScienceDaily,

Engineering researchers have invented an advanced brain-computer interface with a flexible and moldable backing and penetrating microneedles. Adding a flexible backing to this kind of brain-computer interface allows the device to more evenly conform to the brain’s complex curved surface and to more uniformly distribute the microneedles that pierce the cortex. The microneedles, which are 10 times thinner than the human hair, protrude from the flexible backing, penetrate the surface of the brain tissue without piercing surface venules, and record signals from nearby nerve cells evenly across a wide area of the cortex.

This novel brain-computer interface has thus far been tested in rodents. The details were published online on February 25 [2022] in the journal Advanced Functional Materials. This work is led by a team in the lab of electrical engineering professor Shadi Dayeh at the University of California San Diego, together with researchers at Boston University led by biomedical engineering professor Anna Devor.

Caption: Artist rendition of the flexible, conformable, transparent backing of the new brain-computer interface with penetrating microneedles developed by a team led by engineers at the University of California San Diego in the laboratory of electrical engineering professor Shadi Dayeh. The smaller illustration at bottom left shows the current technology in experimental use called Utah Arrays. Credit: Shadi Dayeh / UC San Diego / SayoStudio

A March 14, 2022 University of California at San Diego news release (also on EurekAlert but published March 15, 2022), which originated the news item, delves further into the topic,

This new brain-computer interface is on par with and outperforms the “Utah Array,” which is the existing gold standard for brain-computer interfaces with penetrating microneedles. The Utah Array has been demonstrated to help stroke victims and people with spinal cord injury. People with implanted Utah Arrays are able to use their thoughts to control robotic limbs and other devices in order to restore some everyday activities such as moving objects.

The backing of the new brain-computer interface is flexible, conformable, and reconfigurable, while the Utah Array has a hard and inflexible backing. The flexibility and conformability of the backing of the novel microneedle-array favors closer contact between the brain and the electrodes, which allows for better and more uniform recording of the brain-activity signals. Working with rodents as model species, the researchers have demonstrated stable broadband recordings producing robust signals for the duration of the implant which lasted 196 days. 

In addition, the way the soft-backed brain-computer interfaces are manufactured allows for larger sensing surfaces, which means that a significantly larger area of the brain surface can be monitored simultaneously. In the Advanced Functional Materials paper, the researchers demonstrate that a penetrating microneedle array with 1,024 microneedles successfully recorded signals triggered by precise stimuli from the brains of rats. This represents ten times more microneedles and ten times the area of brain coverage, compared to current technologies.

Thinner and transparent backings

These soft-backed brain-computer interfaces are thinner and lighter than the traditional, glass backings of these kinds of brain-computer interfaces. The researchers note in their Advanced Functional Materials paper that light, flexible backings may reduce irritation of the brain tissue that contacts the arrays of sensors. 

The flexible backings are also transparent. In the new paper, the researchers demonstrate that this transparency can be leveraged to perform fundamental neuroscience research involving animal models that would not be possible otherwise. The team, for example, demonstrated simultaneous electrical recording from arrays of penetrating micro-needles as well as optogenetic photostimulation.

Two-sided lithographic manufacturing

The flexibility, larger microneedle array footprints, reconfigurability and transparency of the backings of the new brain sensors are all thanks to the double-sided lithography approach the researchers used. 

Conceptually, starting from a rigid silicon wafer, the team’s manufacturing process allows them to build microscopic circuits and devices on both sides of the rigid silicon wafer. On one side, a flexible, transparent film is added on top of the silicon wafer. Within this film, a bilayer of titanium and gold traces is embedded so that the traces line up with where the needles will be manufactured on the other side of the silicon wafer. 

Working from the other side, after the flexible film has been added, all the silicon is etched away, except for free-standing, thin, pointed columns of silicon. These pointed columns of silicon are, in fact, the microneedles, and their bases align with the titanium-gold traces within the flexible layer that remains after the silicon has been etched away. These titanium-gold traces are patterned via standard and scalable microfabrication techniques, allowing scalable production with minimal manual labor. The manufacturing process offers the possibility of flexible array design and scalability to tens of thousands of microneedles.  

Toward closed-loop systems

Looking to the future, penetrating microneedle arrays with large spatial coverage will be needed to improve brain-machine interfaces to the point that they can be used in “closed-loop systems” that can help individuals with severely limited mobility. For example, this kind of closed-loop system might offer a person using a robotic hand real-time tactical feedback on the objects the robotic hand is grasping.  

Tactile sensors on the robotic hand would sense the hardness, texture, and weight of an object. This information recorded by the sensors would be translated into electrical stimulation patterns which travel through wires outside the body to the brain-computer interface with penetrating microneedles. These electrical signals would provide information directly to the person’s brain about the hardness, texture, and weight of the object. In turn, the person would adjust their grasp strength based on sensed information directly from the robotic arm. 

This is just one example of the kind of closed-loop system that could be possible once penetrating microneedle arrays can be made larger to conform to the brain and coordinate activity across the “command” and “feedback” centers of the brain.

Previously, the Dayeh laboratory invented and demonstrated the kinds of tactile sensors that would be needed for this kind of application, as highlighted in this video.

Pathway to commercialization

The advanced dual-side lithographic microfabrication processes described in this paper are patented (US 10856764). Dayeh co-founded Precision Neurotek Inc. to translate technologies innovated in his laboratory to advance state of the art in clinical practice and to advance the fields of neuroscience and neurophysiology.

Here’s a link to and a citation for the paper,

Scalable Thousand Channel Penetrating Microneedle Arrays on Flex for Multimodal and Large Area Coverage BrainMachine Interfaces by Sang Heon Lee, Martin Thunemann, Keundong Lee, Daniel R. Cleary, Karen J. Tonsfeldt, Hongseok Oh, Farid Azzazy, Youngbin Tchoe, Andrew M. Bourhis, Lorraine Hossain, Yun Goo Ro, Atsunori Tanaka, Kıvılcım Kılıç, Anna Devor, Shadi A. Dayeh. Advanced Functional Materials DOI: https://doi.org/10.1002/adfm.202112045 First published (online): 25 February 2022

This paper is open access.