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Thermal Transistor: The World's Tiniest Refrigerator

Thermal transistors refrigerate one electron at a time and physicists plan to compute with heat

3 min read

1 January 2008—Traditionally, heat and electronics don’t agree. But physicists in Europe and Asia are beginning to see some signs of cooperation. A Finnish-Italian team has demonstrated that electrons in a specially designed transistor can carry away heat, making the device they built the smallest known refrigerator. Another team, from Singapore, has shown that heat can carry information in a transistor-like device, just like electrons do in conventional computers.

Researchers from the Helsinki University of Technology, in Finland, and the Scuola Normale Superiore in Pisa, Italy, have created a tiny transistor—resembling in structure if not in composition the field-effect transistors in ICs—that they call a single-electron refrigerator. Two superconducting electrodes are connected to a small micrometer-sized copper slab, about 2 mm long and 1/5 mm wide. These electrodes are analogous to the source and drain of a conventional transistor, except that they are electrically isolated from the copper by a thin layer of aluminum oxide. (Two extra electrodes are attached on both sides of the source and drain for measurement purposes.) Along the copper island is placed the ”gate,” an electrode that controls the flow of electrons through the copper slab.

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Are You Ready for Workplace Brain Scanning?

Extracting and using brain data will make workers happier and more productive, backers say

11 min read
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A photo collage showing a man wearing a eeg headset while looking at a computer screen.
Nadia Radic
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Get ready: Neurotechnology is coming to the workplace. Neural sensors are now reliable and affordable enough to support commercial pilot projects that extract productivity-enhancing data from workers’ brains. These projects aren’t confined to specialized workplaces; they’re also happening in offices, factories, farms, and airports. The companies and people behind these neurotech devices are certain that they will improve our lives. But there are serious questions about whether work should be organized around certain functions of the brain, rather than the person as a whole.

To be clear, the kind of neurotech that’s currently available is nowhere close to reading minds. Sensors detect electrical activity across different areas of the brain, and the patterns in that activity can be broadly correlated with different feelings or physiological responses, such as stress, focus, or a reaction to external stimuli. These data can be exploited to make workers more efficient—and, proponents of the technology say, to make them happier. Two of the most interesting innovators in this field are the Israel-based startup InnerEye, which aims to give workers superhuman abilities, and Emotiv, a Silicon Valley neurotech company that’s bringing a brain-tracking wearable to office workers, including those working remotely.

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