Scientists from Cornell University in the United States and Nanyang Technological University in Singapore jointly published a research paper in the journal Nature Electronics on the 3rd, stating that they have developed a neural implant smaller than a salt grain that can continuously wirelessly transmit brain activity data in living animals for more than a year. This device, called "Microscale Optoelectronic Cordless Electrode" (MOTE), has a length of approximately 300 microns and a width of approximately 70 microns. It uses aluminum gallium arsenide semiconductor diodes to obtain energy through harmless red and infrared laser beams that penetrate brain tissue. The low-noise amplifier and optical encoder in the device are both manufactured using mature semiconductor technology found in everyday microchips, capable of encoding brain electrical signals into infrared light pulses and transmitting them wirelessly. The research team stated that as far as we know, this is the world's smallest neural implant device, which can not only detect brain electrical activity but also achieve wireless data transmission. This device adopts pulse position modulation coding technology (similar to satellite optical communication technology), which can achieve efficient optical data transmission with extremely low power consumption. The team first tested the performance of MOTE in a cell culture environment, and then implanted it into the barrel cortex of mice - a key brain area that processes whisker sensory information. During a year long experiment, the implant successfully recorded the peak electrical activity of neurons and a wider range of synaptic activity patterns, while the mice remained healthy and active throughout this period. The team's goal is to make the device small enough to minimize interference with brain tissue, while capturing brain activity faster than imaging systems without the need for genetic modification of neurons. Another major advantage of MOTE is that it can synchronously collect brain electrical signals during magnetic resonance imaging scans, which is difficult to achieve for most existing implant devices. In addition, this technology can also be extended to other tissues such as the spinal cord in the future, and can even be combined with innovative technologies such as optoelectronic devices embedded in artificial skull plates. (New Society)