Human beings are known for many different things, but most importantly of all, they are known for getting better on a consistent basis. This tendency to improve, no matter the situation, has brought the world some huge milestones, with technology appearing as quite a major member of the stated group. The reason why we hold technology in such a high regard is, by and large, predicated upon its skill-set, which ushered us towards a reality that nobody could have ever imagined otherwise. Nevertheless, if we look beyond the surface for a second, it should become clear how the whole runner was also very much inspired from the way we applied those skills across a real world environment. The latter component, in fact, did a lot to give the creation a spectrum-wide presence and start what was a full-blown tech revolution. Of course, this revolution then went on to scale up our experience from many different directions, but even after achieving a feat so notable, technology will somehow continue to bring forth the right goods. The same has turned more and more evident in recent times, and assuming one new discovery ends up with the desired impact, it will only put that trend on a higher pedestal moving forward.   

The researching team at Penn State University has successfully developed a new designed to make those thermoelectric devices more energy efficient than what has looked possible up until now. To give you a quick lowdown, thermoelectric devices are used for converting waste heat to clean electricity, and as they have no moving parts and produce no chemical reactions or emissions, their prospects in the clean energy space are notably impressive. However, considering the conventional version of thermoelectric generators uses different materials to optimize performance on the higher- and lower-temperature sides of the device, it often creates a heterogeneous interface, which in turn, can reduce the device’s efficiency. The new approach, interestingly enough, leverages a single-step procedure to create higher- and lower-temperature side materials to eliminate the need for that interface altogether. Talk about how the whole thing was realized on a more practical note, the researchers used a process called electrical and mechanical field-assisted sintering to create the stated materials. Here, they brought in electric current and pressure to compress fine powders into a solid mass of material. Now, by placing powders one underneath another, the team was able to manufacture functionally graded materials. Furthermore, through some help from dopants, they also managed to tailor the layers. All in all, the resulting flexibility enabled the team to optimize chemical compositions of the higher- and lower-temperature sides, while simultaneously using materials from the same family that can be sintered at similar temperatures in one go.

Another detail worth a mention is that, owing to materials being from the same family, they also bring closely matched thermal expansion and other mechanical properties to allow devices in terms of having a longer operational life.

“Because of global greenhouse gas emissions and the associated environmental issues, we want to move toward greener technologies,” said Bed Poudel, research professor in the Department of Materials Science and Engineering at Penn State University. “This work making thermoelectric devices more efficient can help with that goal.”

Hold on, there is more, as the future might hold an even better version of this methodology. You see, thermoelectric devices resemble a table with two legs—one leg made of p-type and one of n-type semiconductor material, with the current study only applying to the p-type material. Hence, if we are also able to extract the benefits of n-type material, then there is a chance that we can go ahead and unlock substantially higher efficiency benchmarks.

“What we demonstrated by generating 15% conversion efficiency is now this technology is very much competitive with other power generation technologies at the smallest scale—like small diesel generators or even solar panels,” Poudel said. “We show heat energy can be converted into electricity in a competitive way with those technologies.”