Thermoelectric Power Generation

Thermoelectric (TE) materials could play a key role in future technologies. Although the applications of these remarkable compounds have long been explored, they are mostly limited to high-temperature devices. Recently, researchers at Osaka University, in collaboration with Hitachi, Ltd., developed a new TE material with an improved power factor at room temperature. Their study, published in Physica Status Solidi RRL, could help bring these materials out of the high-temperature niche and into the mainstream.

TE materials display the thermoelectric effect: apply heat on one side, and an electric current starts to flow. Conversely, run an external current through the device, and a  temperature gradient forms; i.e., one side becomes hotter than the other. By interconverting heat and electricity, TE materials can be used as either power generators (given a heat source) or refrigerators (given a power supply).

The ideal TE material combines high electrical conductivity, allowing the current to flow, with low thermal conductivity, which prevents the temperature gradient from evening out. The power generation performance mainly depends on the “power factor,” which is proportional to both electrical conductivity and a term called the Seebeck coefficient.

Unfortunately, most TE materials are often based on rare or toxic elements,” according to study co-author Sora-at Tanusilp. “To address this, we combined silicon – which is common in TE materials – with ytterbium, to create ytterbium silicide [YbSi2]. We chose ytterbium over other metals for several reasons. First, its compounds are good electrical conductors. Second, YbSi2 is non-toxic. Moreover, this compound has a specific property called valence fluctuation that make it a good TE material at low temperatures.


Artificial Intelligence Tracks In Real Time Everybody In The Crowd

Artificial Intelligence that can pick you out in a crowd and then track your every move. Japanese firm Hitachi‘s new imaging system locks on to at least 100 different characteristics of an individual … including gender, age, hair style, clothes, and mannerisms. Hitachi says it provides real-time tracking and monitoring of crowded areas.


Until now, we need a lot of security guards and people to review security camera footage. We developed this AI software in the hopes it would help them do just that,” says Tomokazu Murakami, Hitachi researcher.

The system can help spot a suspicious individual or find a missing child, the makers say. So, an eyewitness could provide a limited description, with the AI software quickly scanning its database for a match.
In Japan, the demand for such technology is increasing because of the Tokyo 2020 Olympics, but for us we’re developing it in a way so that it can be utilized in many different places such as train stations, stadiums, and even shopping malls,” comments Tomokazu Murakami.

High-speed tracking of individuals such as this will undoubtedly have its critics. But as Japan prepares to host the 2020 Olympics, Hitachi insists its system can contribute to public safety and security.