Self Healing Roads, Passive Indoor Dehumidifiers and The Grapes of Math
February 27
This week we discover a new development in the quest for roads that repair their own potholes. We examine a new material that can dehumidify a crowded room and we investigate a material with the strength of steel but the weight of Styrofoam. Finally we look into The Grapes of Math where ordinary grapes are used to improve Quantum Senses (apologies to Steinbeck but the researchers at Macquarie Uni came up with this title for their quantum sensor breakthrough).
Self Healing Roads
Potholes in roads in the UK cost approximately GBP150 Million annually to repair. A team from Swansea University and King’s College London in collaboration with a team in Chile have designed a new type of self healing asphalt that can mend its own cracks without the need for human intervention.
Cracks will form when bitumen hardens through oxidation. The team found a way to reverse this cracking and they developed a method to stitch the asphalt back together. The team used an AI to study the organic molecules in complex fluids like bitumen to develop this process.
To make the asphalt self healing they incorporated tiny porous materials known as spores. The spores are smaller than a strand of human hair and as the name suggests they are produced by plants. The spores are filled with recycled oils. These oils are released when the asphalt begins to crack. This helps reverse the process. Lab experiments showed a micro crack self healing within an hour.
The biomass waste used in the process is cheap and available everywhere. Using these materials in new asphalt roads that can heal themselves will increase the durability of roads and reduce the need for people to fill in potholes.
Passive Dehumidification Indoors
The mechanical ventilation systems used to dehumidify indoor environments are costly and depend upon electricity to operate. A team from ETH Zurich have developed a new passive way to have humidity absorbed by walls and ceilings and temporally stored there.
The team started with the finely ground waste from marble quarries. A binder is used to turn this powder into moisture binding wall and ceiling components. The geopolymer binder used consists of metakaolin (from porcelain production) and an alkaline solution of potassium silicate and water. The alkaline solution activates the metakaolin and provides a geoplolymer binder to causes the marble powder to form a solid building material similar to cement.
A 3D printing process was used to apply the marble powder in layers which was then glued by the geopolymer binder. This allows the efficient production of a wide variety of shapes.
The product is best used in areas which have people coming and going in large groups. When rooms fill with people the relative humidity rises. Once they leave the building ventilation will reduce the excess humidity. With these wall or ceiling tiles, the excess humidity is stored in the tiles when people congregate in the room. the humidity is then naturally released when they leave and the normal building ventilation takes over.
A reading room in a public library in Oporto Portugal was used to simulate the effect of the materials. The room was used by up to 15 individuals. A discomfort index was developed based upon the increase in the relative humidity as more people used the room. Fitting the room with the 4cm thick moisture binding components reduced the discomfort index by 75%. Using 5cm thick materials reduced the discomfort index by 85%. Not requiring ventilation systems to dehumidify spaces when crowds assemble reduces the cost of ventilation significantly.
Steel Strong Foam Light Materials
A team at the University of Toronto has designed a nano architected material that has the strength of carbon steel but the lightness of Styrofoam. These nano materials have exceptional strength, light weight and customizability.
Nano architected materials are made of tiny building blocks measuring a few hundred nanometers in size. 100 of them patterned in a row would be as thick as a human hair. The building blocks are made of carbon and arranged in complex 3D structures called nano lattices.
A multi objective Bayesian optimization machine learning algorithm was used to predict the best possible geometries for enhancing stress distribution and improving the strength to weight ratio of the designs. The algorithm learned as it tested more designs of what worked and what didn’t.
Prototypes were then 3D printed for validation. The optimized lattices more then doubled the strength of existing designs withstanding stresses of 2.03 megapascal for every cubic meter per kilogram of density. This is 5 times higher than Titanium. These new materials may find uses in a range of industries from automotive to aerospace.
The Grapes of Math
A team at Macquarie University in Sydney have demonstrated how ordinary grapes can enhance the performance of quantum sensors. This has the potential to lead to more efficient quantum technologies.
The team found that pairs of grapes can create strong localized magnetic field hotspots of microwaves which are used in quantum sensing applications. The research was inspired by social media videos of grapes creating plasma glowing balls of electrically charged particles in microwave ovens (see you are not wasting your time doomscrolling on TikTok, it is actually scientific research).
The team used specialized nano-diamonds containing nitrogen-vacancy centers (i.e. atomic scale defects that act as quantum sensors). The defects behave like tiny magnets and can detect magnetic fields.
The sensor was placed on the tip of a glass fibre and positioned between two grapes. By shining green laser light through the fiber, they could make the atoms glow red. The brightness of the red glow revealed the strength of the microwave field around the grapes.
The size and shape of the grapes was important for the experiments success. Each grape was 27 millimeters long. This allowed the concentration of microwave energy at the right frequency for the diamond sensor.
The finding unlocks a new avenue for exploring alternative microwave resonator designs for quantum technologies. Possibly leading to more compact and efficient sensing devices. The team is now looking for more reliable materials beyond supermarket grapes to achieve the same effect.
Paying it Forward
If you have a start-up or know of a start-up that has a product ready for market please let me know. I would be happy to have a look and feature the startup in this newsletter. Also if any startups need introductions please get in touch and I will help where I can.
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