It’s an amazing breakthrough – researchers have developed an LED device that can remotely control a mouse. The glowing device is the size of a peppercorn and is a leap forward in this field of research.

Optogenetics allows researchers to target specific cells or proteins in the brain with light. The potential impact of optogenetics has been restricted by the fiber optic cable researchers have had to attach to the brain of a mouse to deliver light and control nerves. These clunky cables prevented the mice from moving much, which limited the scope of the research. Now, researchers have developed a new technique of carrying out optogenetics wirelessly.

Ada Poon, an assistant professor of electrical engineering at Stanford University, developed an implantable, wirelessly powered device. It wasn’t until she attended a neural engineering workshop that she realized the potential the device could have in the field of optogenetics. She teamed up with other bio and mechanical engineers to develop a light-delivery device that contained a circuit, a power-receiving coil and LEDs. The researchers had to then find a way to power the device over a large area without compromising its efficiency.

Poon and her research team decided to use the mouse’s own body to extract the energy their device needed. As the video below explains, researchers developed a small chamber called a “resonant cavity.” This cavity confines electromagnetic fields inside it when it’s excited by radio frequency. Researchers covered the cavity with a honeycomb structure to trap the energy inside the chamber, preventing it from radiating in different directions. When researchers place the mouse on the chamber, it’s able to harness the energy with the power-receiving coil in the implant.

The wireless device weighs only 20 to 50 milligrams, making it small enough to fit into a mouse’s skull, spine or limbs. To see whether the device works, researchers used it to stimulate neurons and spinal cord nerves. They were able to make the mice walk in circles across the chamber.

As researchers point out, this isn’t going to become a weapon used against humans. The important caveat to optogenetics is that it only works on proteins that have been specifically prepared to respond to light. The mice they control wirelessly were bred to contain these proteins, or were injected with viruses containing the genes for the proteins. Shining a light on a neuron that hasn’t undergone this process simply wouldn’t work.

In the study, published in Nature Methods, researchers suggest this new technique could lead to the development of new experiments to better understand and treat a range of diseases and mental health disorders.