The concept of energy harvesting with flexible thermoelectrics shown with a schematic of aerosol jet printing.
CREDIT: Injung Lee
Nontoxic, nanotube-based thermoelectric generation converts uneven heat distribution from wearables to electrical energy for their next cycle of operation
A wide variety of portable and wearable electronics have become a large part of our daily lives, so a group of Stanford University researchers wondered if these could be powered by harvesting electricity from the waste heat that exists all around us.
Further inspiration came from a desire to ultimately fabricate energy converting devices from the same materials as the active devices themselves, so they can blend in as an integral part of the total system. Today, many biomedical nanodevices’ power supplies come from several types of batteries that must be separated from the active portion of the systems, which is not ideal.
In Applied Physics Letters, from AIP Publishing, the researchers report the design and fabrication of single-wall carbon nanotube thermoelectric devices on flexible polyimide substrates as a basis for wearable energy converters.
“Carbon nanotubes are one-dimensional materials, known for good thermoelectric properties, which mean developing a voltage across them in a temperature gradient,” said Eric Pop, a professor of electrical engineering and materials science. “The challenge is that carbon nanotubes also have high thermal conductivity, meaning it’s difficult to maintain a thermal gradient across them, and they have been hard to assemble them into thermoelectric generators at low cost.”
The group uses printed carbon nanotube networks to tackle both challenges.
“For example, carbon nanotube spaghetti networks have much lower thermal conductivity than carbon nanotubes taken alone, due to the presence of junctions in the networks, which block heat flow,” Pop said. “Also, direct printing such carbon nanotube networks can significantly reduce their cost when they are scaled up.”
Thermoelectric devices generate electric power locally “by reusing waste heat from personal devices, appliances, vehicles, commercial and industrial processes, computer servers, time-varying solar illumination, and even the human body,” said Hye Ryoung Lee, lead author and a research scientist.
“To eliminate hindrances to large-scale application of thermoelectric materials — toxicity, materials scarcity, mechanical brittleness — carbon nanotubes offer an excellent alternative to other commonly used materials,” Lee said.
The group’s approach demonstrates a path to using carbon nanotubes with printable electrodes on flexible polymer substrates in a process anticipated to be economical for large-volume manufacturing. It is also “greener” than other processes, because water is used as the solvent and additional dopants are avoided.
Flexible and wearable energy harvesters can be embedded into fabrics or clothes or placed on unusual shapes and form factors.
“In contrast, traditional thermoelectrics that rely on bismuth telluride are brittle and stiff, with limited applications,” Pop said. “Carbon-based thermoelectrics are also more environmentally friendly than those based on rare or toxic materials like bismuth and tellurium.”
The most important concept in the group’s work is to “recycle energy as much as we can, converting uneven heat distribution to electrical energy for use for the next cycle of operation, which we demonstrated by using nontoxic nanotube-based thermoelectric generation,” said Yoshio Nishi, a professor of electrical engineering. “This concept is in full alliance with the world’s goal of reducing our total energy consumption.”
Original Article: Nontoxic, flexible energy converters could power wearable devices
More from: Stanford University
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Flexible energy converters
- Six key actions to expedite offshore wind deployment
The offshore wind power sector will play a vital role in the energy transition as it is expected to increase by 40-fold within the next 30 years to contribute to maintaining clean energy targets. ERM ...
- Andes LNG project deemed ‘feasible’, includes 400 MW power plant
Andes LNG Terminal, consisting of a regas facility and 400 MW gas-fired power station, has been assessed as ‘feasible’ by Black & Veach. The ...
- US coal-fired power generation bound to fall for fourth year in a row
Coal is on the way out in the US power mix, with hourly dispatch of coal-fired generation forecast to fall for the fourth consecutive year, having ...
- Vertex pivoting Mobile refinery hydrocracker back to conventional from renewable service
Vertex Energy will return the hydrocracker at its Alabama refining complex back to conventional service by yearend 2024.
- Transforming common soft magnets into next-generation thermoelectric conversion materials with 3-minute heat treatment
A research team from NIMS and Nagoya University has demonstrated that an iron-based amorphous alloy, widely used as a soft magnetic material in transformers and motors, can be transformed into a ...
Go deeper with Google Headlines on:
Flexible energy converters
[google_news title=”” keyword=”flexible energy converters” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]
Go deeper with Bing News on:
Nanotube-based thermoelectric generation
- Transforming common soft magnets into next-generation thermoelectric conversion materials with 3-minute heat treatment
A research team from NIMS and Nagoya University has demonstrated that an iron-based amorphous alloy, widely used as a soft magnetic material in transformers and motors, can be transformed into a ...
- Transforming common soft magnets into a next-generation thermoelectric conversion materials by 3 minutes heat treatment
A research team has demonstrated that an iron-based amorphous alloy, widely used as a soft magnetic material in transformers and motors, can be transformed into a 'transverse' thermoelectric ...
- Ion thermoelectric conversion devices for near room temperature
Prof. Zeng Wei of the Institute of Chemical Engineering, Guangdong Academy of Sciences, said that at the beginning, the research team mainly carried out study based on the thermal diffusion effect ...
- Ion thermoelectric conversion devices for near room temperature
They published their work in Energy Material Advances ("Energy Density in Ionic Thermoelectric Generators by Prussian Blue Electrodes ... the group mainly carried out research based on the thermal ...
- India directs gas-based power plants to maximise generation during summer
The order will run from 1 May to 30 June. The Indian government ordered gas-based generating stations to maximise their power generation to meet the high electricity demand during the summer ...
Go deeper with Google Headlines on:
Nanotube-based thermoelectric generation
[google_news title=”” keyword=”nanotube-based thermoelectric generation” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]