Scientists at MIT have developed a groundbreaking technology that uses tiny, wireless antennas to monitor how cells communicate.
These antennas, called OCEANs (organic electro-scattering antennas), use light to detect small electrical signals, eliminating the need for wires and making it easier to study biological systems.
This innovation could lead to better understanding of diseases like arrhythmia and Alzheimer's and pave the way for improved treatments and diagnostics.
Cells in the body use electrical signals to communicate, just like neurons firing in the brain or heart cells coordinating a heartbeat.
Understanding these signals is crucial for studying how cells work and what goes wrong in diseases.
Traditional devices for monitoring electrical signals rely on wires and amplifiers, which limit the number of signals that can be recorded at once. This restricts the information scientists can gather about cellular communication.
To solve this problem, MIT researchers developed a wireless, light-based system that can measure these signals with extreme precision and high resolution.
Instead of using wires, the tiny antennas detect electrical signals by scattering light in response to changes in the environment.
The OCEANs are made from a special polymer called PEDOT:PSS. This material interacts with the ions in the surrounding liquid environment. When there is electrical activity near the antennas, the polymer attracts or repels positive ions, changing its chemical structure.
This affects a property called the refractive index, altering how the polymer scatters light.
To record these changes, scientists shine light onto the antennas. The intensity of the scattered light changes in proportion to the electrical signals in the liquid.
Using an optical microscope, researchers can capture the scattered light and decode the electrical signals.
Each antenna is only 1 micrometer wide -- about 100 times thinner than a human hair.
Because the antennas are so small, scientists can create arrays with thousands or even millions of them, allowing them to monitor electrical signals from many cells simultaneously.
The antennas can record signals with micrometer precision, making them ideal for detailed studies of cellular communication.
To make the antennas, researchers start with a glass base and add layers of conductive and insulating materials, which are transparent to light.
They then use a high-tech tool, called a focused ion beam, to create nanoscale holes in these layers. Next, the chip is submerged in a solution containing the building blocks of the polymer.
By applying an electric current, the polymer material fills the holes and forms mushroom-shaped antennas from the bottom up.
The process is quick and scalable, meaning it's possible to produce chips with millions of antennas. This fabrication technique, developed at MIT.nano, allows for precise control over the size and shape of the antennas, which is key to their high sensitivity.
The OCEAN technology has several major advantages. First, it eliminates the need for wires or amplifiers, making it simpler and easier for biologists to use.
Second, it can monitor electrical signals with incredibly high spatial resolution, meaning scientists can see how individual cells communicate.
Third, the antennas are sensitive enough to detect signals as small as 2.5 millivolts. For comparison, neurons in the brain usually send signals around 100 millivolts, so this technology is more than capable of studying cellular activity.
Another advantage is speed: OCEANs respond to changes in just a few milliseconds, making them ideal for recording fast electrical signals. The devices are durable, able to continuously record signals for over 10 hours, and can be used in experiments where cells are grown directly on top of the antenna arrays.
The researchers plan to test OCEANs with real cell cultures to study how cells communicate in response to changes in their environment. They also want to reshape the antennas to penetrate cell membranes, enabling even more precise measurements. Additionally, they aim to explore how OCEANs could be used in nanophotonic devices, which manipulate light at the nanoscale for advanced sensors and optical systems.
This innovative technology, supported by research from MIT and collaborators, opens up new possibilities for understanding biology, diagnosing diseases, and developing new therapies. By allowing scientists to study cellular communication more accurately and efficiently, OCEANs could lead to major breakthroughs in medicine and healthcare.