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An army of "U" shaped nanowire devices could accelerate research on how brain and cardiac cells communicate. Here, a device crosses the membrane barrier of a neuron in order to record intracellular chatter. (Credit: Lieber Group, Harvard University)

Soon, so-called brain-machine interfaces could: monitor and treat symptoms of neurological disorders like Parkinson’s disease, provide a blueprint to design artificial intelligence, or even enable brain-to-brain communication.

To achieve the reachable and quixotic, devices need a way to literally dive deeper into our cells to perform reconnaissance. The more we know about how neurons work, the more we can emulate, replicate, and treat them with our machines.

Researchers have designed a way to make thousands of nanoscale devices for intracellular recording at once, creating a nanoscale army that could speed efforts to find out what’s happening inside our cells.

Designed in 2010, the originals had a nanoscale V-shaped tip with a transistor at the bottom of the V. This design could pierce cell membranes and send accurate data back without destroying the cell. But there was a problem. Silicon nanowires are far longer than they are wide, making them wobbly and hard to wrangle.

To create the original devices, lab members had to ensnare one nanowire noodle at a time, find each arm of the V, and then weave the wires into the recording device. Two devices took two to three weeks to make. “It was very tedious work,” said Zhang.

But nanowires are not made one at a time; they’re made en masse like the thing they resemble: cooked spaghetti. Using the nanocluster catalyzed vapor-liquid-solid method, with which researchers created the first nanowires, the team built an environment where the wires could germinate on their own. They can pre-determine each wire’s diameter and length but not how the wires are positioned once ready. Even though they grow thousands or even millions of nanowires at a time, the end result is a tangled mess.

With a “combing” method, researchers complete hundreds of nanowire devices in the same amount of time they used to make just a couple. So far, they have used the “U” shaped nanoscale devices to record intracellular signals in both neural and cardiac cells in cultures. Coated with a substance that mimics the feel of a cell membrane, the nanowires can cross this barrier with minimal effort or damage to the cell. And, they can record intracellular chatter with the same level of precision as their biggest competitor: patch clamp electrodes.

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