Printing in color with photoswitchable polymers

Now, Haifeng Yu and his colleagues from Peking University have introduced a photo-responsive element — an azopolymer — that allows the imprinting of nanopatterns in a novel, room-temperature lithographic process.

The team’s new photosensitive polymer contains a structure called azobenzene, which switches between two possible conformations — termed trans and cis — when irradiated with light. Switching between the two leads to a straight or bent configuration, and when attached to a polymer backbone causes mechanical changes, such a hardening, in the polymer.

During the fabrication process, the azopolymer layer was first liquefied using UV light and then used to coat a flexible plastic surface. 

Chip drastically improves the energy efficiency of the internet

The amount of data sent through fibre optic cables is rising exponentially, increasing energy usage at an unprecedented rate. Researchers may have a solution to render fibre optic communications systems much more energy efficient.

According to researchers from Chalmers University of Technology, Sweden, the increases in power consumption are unsustainable. Without energy efficiency improvements, within ten years the internet alone could consume more electricity than is currently generated worldwide.

Electricity production cannot be increased at the same rate without massively increasing the fossil fuel burning for electricity generation, in turn leading to a significant increase in carbon emissions.

For five years, the researchers have been researching how to improve efficiency, and have developed a solution in the form of error-correcting data chip circuits, which they refined to be 10 times less energy consumptive: “The challenge lies in meeting that inevitable demand for capacity and performance, while keeping costs at a reasonable level and minimising the environmental impacts,” says Professor Peter Andrekson, a photonics expert at Chalmers University.

In the early phase of the project, the researchers identified the largest energy drains in today’s fibre optic systems. They then designed and built a concept for a system for data transmission which consumes as little energy as possible. Some of the most energy-intensive components are error-correction data chips, which are used in optical systems to compensate for noise and interference. The researchers have optimised the circuits in these chips to drastically improve energy efficiency.

At a systemic level, the researchers also demonstrated the advantages of using optical “frequency combs” instead of separate laser transmitters for each frequency channel. An optical frequency comb emits light at all wavelengths simultaneously, making the transmitter highly frequency-stable. This makes reception of the signals much easier, and consequently more energy efficient.

Energy savings can also be made through controlling fibre optic communications at the network level; by mathematically modelling the energy consumption in different network resources, data traffic can be controlled and directed so that the resources are utilised optimally. This is especially valuable if traffic varies over time, as is the case in most networks. For this, the researchers developed an optimisation algorithm which can reduce network energy consumption by up to 70 per cent.

“Improving the energy efficiency of data transmission requires multidisciplinary competence. The challenges lie at the meeting points between optical hardware, communications science, electronic engineering and more. That’s why this project has been so successful” said Professor Erik Agrell.

Bending Diamond

Diamond possess a range of extraordinary properties that make it an exceptional material. Among them is its exceptional mechanical stability and its reputation as one of the hardest known materials in the world. 

a team of Australian scientists have turned this idea of diamond’s indisputable hardness on its head; having discovered that diamond can actually be bent and deformed … that is, on the nanoscale.