Technology Trending: solar energy harvesting, 3D printed batteries, nuclear fission rocket engines
Self-assembling nanoparticles for solar-thermal energy harvesting, 3D printed solid state batteries and nuclear fission rocket engines for deep space travel are on this week’s technology radar.
Self-assembling nanoparticles to harvest solar energy
Solar-thermal technology such as concentrated solar power or on a smaller scale solar water heating is a promising option for growing renewables penetration but it is challenged by suppressing the energy dissipation while maintaining a high absorption.
But now researchers from Harbin University, Zhejiang University, Changchun Institute of Optics, and the National University of Singapore believe they can overcome this challenge with an absorber comprised of iron oxide nanoparticles that self-assemble to form an organised quasi-periodic material structure based on their interactions with nearby particles without any external instructions.
This structure, which is scalable, was found to provide a significant solar absorption >94% and ideal passive suppression of thermal emissivity <0.2. Tested under natural sunlight, the harvester reached a sustaining open circuit voltage of >20mV/cm2 without a heat sink.
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With further work, the researchers believe the technology should pioneer next generation, high performance, economical, and practical solar co-harvesting systems.
3D printed solid state batteries
As the need for batteries increases, new technologies and new methods of production are required to meet the energy and demand requirements.
One of these is 3D printing which allows the production of complex shapes and geometries and now Silicon Valley 3D printing startup Sakuú – formerly KeraCel – has announced what it calls the “first-of-its-kind recorded manufacturing achievement” of the successful and consistent 3D printing of fully functional performant batteries in custom shapes and sizes at its pilot facility.
Sakuu is using its own manufacturing method comprised of a proprietary multi-material, multi-layer approach in a parallel and dry process, which is declared able to deliver a low cost high speed manufacturing capability coupled with flexibility in shape and form, while also delivering batteries in core categories that matter most to clients and customers alike.
“We believe we have the only known solution for manufacturing solid state batteries at scale with our novel Kavian platform,” says Sakuu founder and CEO Robert Bagheri.
“Printing custom patterned batteries using a dry process that starts with raw material and concludes with a fully functional high performance battery is a breakthrough that has the potential to transform how batteries of the future are manufactured for all industries.”
Sakuu plans to sell its Kavian platform to other battery manufacturers as well as leading automotive, e-mobility and aerospace manufacturers who want to mass produce batteries.
The company also intends to license its lithium-metal and solid state chemistries, with the prospect of production in gigafactories worldwide.
Nuclear fission engines for space travel
While nuclear fission continues to attract a mixed reaction for power generation, interest is growing in its potential to power rockets, in particular for deep space missions for example to Mars and beyond with the possibility of reducing the journey time from the months it would take currently down to weeks and the years down to months.
However, the current proposed designs for fission fragment rocket engines are prohibitively massive, have significant thermal constraints or require implementing complex designs, all of which limit their near-term viability.
California based Positron Dynamics’ proposal, which has been awarded stage 1 funding from NASA, is to store the fuel as a gel.
The company is proposing to develop a small prototype low density nuclear reactor core and convert the nuclear energy stored in a fissile material into a high velocity rocket exhaust and electrical power. Key improvements over previous concepts are to embed the fissile fuel particles in an ultra-low density aerogel matrix to achieve a critical mass assembly, while breakthroughs in high field, high temperature superconducting magnets will be utilised to constrain fission fragment trajectories to minimise the reactor mass.
With this Positron Dynamics believes it is possible for a rocket to travel to the solar gravitational lens at a distance of between approximately 80-150 billion km from the sun, i.e. up to a thousand times the distance of the Earth from the Sun and varying according to the direction of observation, within 15 years. There the on board telescope would be able to image a planet around another star system with enough resolution to detect surface features and any signs of habitability.
