Tag Archives: He Tian

An artificial graphene throat

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A July 24, 2019 American Chemical Society (ACS) news release (received via email and also on EurekAlert) describes a ‘tattoo-like- artificial throat derived from graphene,

Most people take speech for granted, but it’s actually a complex process that involves both motions of the mouth and vibrations of folded tissues, called vocal cords, within the throat. If the vocal cords sustain injuries or other lesions, a person can lose the ability to speak. Now, researchers reporting in ACS Nano have developed a wearable artificial throat that, when attached to the neck like a temporary tattoo, can transform throat movements into sounds.

Scientists have developed detectors that measure movements on human skin, such as pulse or heartbeat. However, the devices typically can’t convert these motions into sounds. Recently, He Tian, Yi Yang, Tian-Ling Ren and colleagues developed a prototype artificial throat with both capabilities, but because the device needed to be taped to the skin, it wasn’t comfortable enough to wear for long periods of time. So the researchers wanted to develop a thinner, skin-like artificial throat that would adhere to the neck like a temporary tattoo.

To make their artificial throat, the researchers laser-scribed graphene on a thin sheet of polyvinyl alcohol film. The flexible device measured 0.6 by 1.2 inches, or about double the size of a person’s thumbnail. The researchers used water to attach the film to the skin over a volunteer’s throat and connected it with electrodes to a small armband that contained a circuit board, microcomputer, power amplifier and decoder. When the volunteer noiselessly imitated the throat motions of speech, the instrument converted these movements into emitted sounds, such as the words “OK” and “No.” The researchers say that, in the future, mute people could be trained to generate signals with their throats that the device would translate into speech.

Caption: A wearable artificial graphene throat, abbreviated here as ‘WAGT,’ can transform human throat movements into different sounds with training of the wearer. Credit: Adapted from ACS Nano 2019, 10.1021/acsnano.9b03218

Here’s a link to and a citation for the paper,

A Wearable Skinlike Ultra-Sensitive Artificial Graphene Throat by Yuhong Wei, Yancong Qiao, Guangya Jiang, Yunfan Wang, Fangwei Wang, Mingrui Li, Yunfei Zhao, Ye Tian, Guangyang Gou, Songyao Tan He, Tian, Yi Yang, Tian-Ling Ren. ACS Nano2019XXXXXXXXXX-XXX DOI: https://doi.org/10.1021/acsnano.9b03218 Publication Date: July 3, 2019 Copyright © 2019 American Chemical Society

This paper is behind a paywall.

Hacking the human brain with a junction-based artificial synaptic device

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Earlier today I published a piece featuring Dr. Wei Lu’s work on memristors and the movement to create an artificial brain (my June 28, 2017 posting: Dr. Wei Lu and bio-inspired ‘memristor’ chips). For this posting I’m featuring a non-memristor (if I’ve properly understood the technology) type of artificial synapse. From a June 28, 2017 news item on Nanowerk,

One of the greatest challenges facing artificial intelligence development is understanding the human brain and figuring out how to mimic it.

Now, one group reports in ACS Nano (“Emulating Bilingual Synaptic Response Using a Junction-Based Artificial Synaptic Device”) that they have developed an artificial synapse capable of simulating a fundamental function of our nervous system — the release of inhibitory and stimulatory signals from the same “pre-synaptic” terminal.

Unfortunately, the American Chemical Society news release on EurekAlert, which originated the news item, doesn’t provide too much more detail,

The human nervous system is made up of over 100 trillion synapses, structures that allow neurons to pass electrical and chemical signals to one another. In mammals, these synapses can initiate and inhibit biological messages. Many synapses just relay one type of signal, whereas others can convey both types simultaneously or can switch between the two. To develop artificial intelligence systems that better mimic human learning, cognition and image recognition, researchers are imitating synapses in the lab with electronic components. Most current artificial synapses, however, are only capable of delivering one type of signal. So, Han Wang, Jing Guo and colleagues sought to create an artificial synapse that can reconfigurably send stimulatory and inhibitory signals.

The researchers developed a synaptic device that can reconfigure itself based on voltages applied at the input terminal of the device. A junction made of black phosphorus and tin selenide enables switching between the excitatory and inhibitory signals. This new device is flexible and versatile, which is highly desirable in artificial neural networks. In addition, the artificial synapses may simplify the design and functions of nervous system simulations.

Here’s how I concluded that this is not a memristor-type device (from the paper [first paragraph, final sentence]; a link and citation will follow; Note: Links have been removed)),

The conventional memristor-type [emphasis mine](14-20) and transistor-type(21-25) artificial synapses can realize synaptic functions in a single semiconductor device but lacks the ability [emphasis mine] to dynamically reconfigure between excitatory and inhibitory responses without the addition of a modulating terminal.

Here’s a link to and a citation for the paper,

Emulating Bilingual Synaptic Response Using a Junction-Based Artificial Synaptic Device by
He Tian, Xi Cao, Yujun Xie, Xiaodong Yan, Andrew Kostelec, Don DiMarzio, Cheng Chang, Li-Dong Zhao, Wei Wu, Jesse Tice, Judy J. Cha, Jing Guo, and Han Wang. ACS Nano, Article ASAP DOI: 10.1021/acsnano.7b03033 Publication Date (Web): June 28, 2017

Copyright © 2017 American Chemical Society

This paper is behind a paywall.