MIT-Devised Radio Chip Looks Like the Human Ear

Researchers at the Massachusetts Institute of Technology again proved their worth recently, as they managed to create a low-power, ultra-broadband, fast radio chip that could make wireless devices able to receive phone calls, Internet access, as well as radio and television signals possible. The new chips is shaped after the human inner ear, or the cochlea, operates at a much lower power than others, and is also faster than any existing radio-frequency spectrum analyzers. It was devised by MIT associate professor of electrical engineering and computer science Rahul Sarpeshkar, working with graduate student Soumyajit Mandal.

 

The results of the research are published in the June issue of the IEEE Journal of Solid-State Circuits. ”The cochlea quickly gets the big picture of what's going on in the sound spectrum. The more I started to look at the ear, the more I realized it's like a super radio with 3,500 parallel channels,” said Sarpeshkar of the invention. The two researchers say that the device, dubbed the “radio frequency (RF) cochlea,” can be modified to receive a large array of broadband signals, ranging from cellular phones, wireless Internet, FM, and others. The team has already filed for a patent, to insert its technology into a universal or software radio architecture.

 

The human ear processes sound waves into electrical signals to pass on to the brain in a variety of means, employing piezoelectric, neural signaling and fluid mechanics. This makes it one of the most aptly evolved mechanisms in nature, able to discern between an almost-infinite array of sounds in its auditory range, of 20 to 20,000 hertz. As the sound enters the ear, it mechanically deforms the inner ear and the fluid inside it, creating ripples that activate the hair cells that the area is laden with. These receptors, when moved, create differences in the electrical potential of the region, which are then transmitted to the auditory processing area of the brain, and turned into the hearing sensation.

 

When analyzing the 100 to 10,000 Hz sound range, the MIT team noticed a 100-fold range of frequencies that the inner ear can pick up. They set out to create a device that would record one million-fold frequencies, a range that includes every kind of signal, from Internet, telephone, to Wi-Fi. “Somebody who works in radio would never think of this, and somebody who works in hearing would never think of it, but when you put the two together, each one provides insight into the other,” added Sarpeshkar, revealing that he drew his inspiration from outside his field as well.

“Humans have a long way to go before their architectures will successfully compete with those in nature, especially in situations where ultra-energy-efficient or ultra-low-power operation are paramount. [However], we can mine the intellectual resources of nature to create devices useful to humans, just as we have mined her physical resources in the past,” he concluded.