Researchers at Cornell University have presented a revolutionary breakthrough in neuroscience: a neural implant called MOTE (Microscale Optoelectronic Tetherless Electrode), which is so small it can fit on a single grain of salt.
The device, which is approximately 300 microns long, is the world’s smallest wireless implant capable of transmitting high-quality data on the electrical activity of a living organism’s brain for over a year. MOTE is powered by laser beams that safely pass through brain tissue and uses infrared light pulses to transmit data—a technique that ensures high-quality signal reception with minimal energy consumption.
MOTE’s main advantage is its minimal invasiveness. Unlike traditional implants, researchers reduced its size to minimize damage to brain tissue and the immune response. Experiments conducted on mice confirmed that the implant successfully records the electrical signals of neurons over a long period without causing harm to health.
The research, which was published in the journal Nature Electronics, even allows scientists to use the implant during MRI scans, which was previously very difficult. This technological achievement is a significant step forward toward comprehensive and safe brain research.
Medscriptum prepared an exclusive interview with the lead researchers of this revolutionary wireless neural implant developed by Cornell University: Professor Alyosha Molnar and Professor Sunwoo Lee.
Professor Alyosha Molnar is a Professor in the School of Electrical and Computer Engineering at Cornell University. Notably, Professor Molnar had been attempting to create this implant since the early 2000s and has been actively involved in the project throughout this time. He co-manages the project with Professor Sunwoo Lee, an Assistant Professor at the School of Electrical and Electronic Engineering at Nanyang Technological University in Singapore.
The professors speak in detail about this smallest wireless device in the world, which can transmit high-quality brain activity data for over a year.
Interview with Professor Sunwoo Lee
Your team has created a neural implant so small that it’s almost invisible, yet capable of recording brain activity for long periods. How do you think this level of miniaturization will reshape the future of neuroscience—whether in research, medicine, or the broader relationship between humans and technology?
I think the most important aspect of our work is that we’ve demonstrated it is indeed possible to create something so small yet so intelligent—and capable of lasting so long in the brain. This has been theoretically feasible for some time, but until now it remained out of reach. While our implant alone may not drastically reshape the future of neuroscience, I believe it will inspire greater interest and confidence in developing similarly tiny, untethered implants. These could enable long-term studies that were previously impossible.
As this extreme size reduction decreases invasiveness and lowers costs, we may soon see a proliferation of miniature sensors beyond neural recording—for instance, on or under the skin, measuring biomarkers that current smart wearables cannot detect. Perhaps these sensors could even be integrated with existing wearables, drawing power from them and communicating directly, bridging the current gap between continuous glucose monitors (CGMs) and smart devices. Ultimately, we hope this work will contribute to the generation of large-scale biological data over time—data that could unlock immense AI-driven potential for personalized healthcare, an area where AI still struggles due to limited datasets.
Supplying power and transmitting signals at the microscale has always been one of the biggest engineering challenges. How did you manage to achieve reliable operation without traditional batteries or wiring, and which technological breakthrough proved most crucial in making this possible?
Thank you for the question. Indeed, achieving reliable operation without batteries or wiring was a major challenge for us. We overcame many of these obstacles by actually going “simpler.” We minimized the distance between system components and used direct metal deposition for interconnects instead of wire bonding. It’s somewhat analogous to how transistors evolved over time—the earliest ones were bulky, connected by unstable wires, and were neither scalable nor reliable. Once they transitioned into integrated circuits (for which Jack Kilby won the Nobel Prize in 2000), systems became vastly more stable and scalable. Following that same philosophy helped us resolve many of the issues we initially faced.
Another critical factor was atomic layer deposition (ALD), which allowed us to extend implant longevity without significantly increasing its size. These implants must be protected from biological fluids, essentially “salty water,” and conventional encapsulation methods typically require several micrometers of thickness to compensate for imperfections in film quality. In our case, we used high-fidelity ALD encapsulation, achieving robust protection with only about one micrometer of thickness—a number that may decrease further as we optimize. ALD, traditionally used in producing high-quality gate dielectrics in semiconductor manufacturing, has rarely been considered for this kind of biomedical encapsulation, but we’ve been able to harness its full potential here.
As brain signal monitoring becomes more precise and accessible, new ethical questions naturally arise. In your view, how should we approach data privacy and consent in the age of neural interfaces, and what principles should guide the responsible development of this technology?
That’s a very important question. Unfortunately, guidelines and policies often lag behind technological progress. However, over the past few decades, we’ve developed—though still imperfect—protocols for handling private data generated by social media, the internet, and the digitalization of medical records. I think we should begin with those same principles, as the underlying philosophy remains largely the same.
Proper anonymization will be key to ensuring privacy while still allowing data to be used for positive purposes, such as enabling personalized healthcare and the development of biological “digital twins.” Separately, my group is collaborating with other teams to develop more secure protocols—both at the hardware and software levels—to address privacy and data protection concerns more effectively.
When do you foresee ultra-small implants like this playing a real role in diagnosing or treating neurological disorders such as epilepsy or depression? Do you see a path for this technology to eventually become a standard medical tool?
I believe ultra-small implants like ours could make a significant difference in chronic studies and monitoring applications that require minimally invasive biological recording—whether within the brain or under the skin, similar to commercial continuous glucose monitors (CGMs). There are also ongoing studies exploring the use of such implants for neural stimulation or drug delivery, which could pave the way for therapeutic, rather than purely diagnostic, use.
Personally, I hope that miniature implants like ours will offer an affordable and nearly imperceptible means of long-term monitoring, enabling the early detection of diseases before they progress. This would allow interventions through minor medication or lifestyle adjustments—an ideal scenario that avoids the need for surgery or intensive treatment.
If we follow this line of research ten years into the future, where do you think we’ll be? What kind of neural implants do you imagine the next generation will bring, and how might they change our understanding of consciousness, memory, or thought itself?
We are currently optimizing our implant and plan to distribute it to researchers interested in using it, while actively collecting their feedback. I believe we’ll continue to work on ultra-small yet intelligent implantable systems, though the specific applications will evolve according to the field’s most pressing needs.
What we’ve enabled here—chronic neural activity monitoring in a highly minimally invasive way—could lead to discoveries that surprise us all. There is still so much we don’t fully understand about the brain, which makes this field even more fascinating in the age of AI. We hope our technology will contribute to a deeper understanding of ourselves.
