Scientists have created a radically new type of graphene speakers

Practically all the existing dynamics work on the same principle: the electric signal generates oscillations of the coil in the field of a permanent magnet, it drives the diffuser, and this, in turn, creates air vibrations and sound waves of the required frequency. But in the future, everything can change, because scientists from the British University of Exeter have created a fundamentally new type of dynamics from graphene, which does not need any mechanical vibration.

The principle of the new dynamics is based on a change in the temperature of graphene, the changes of which lead to the appearance of sound. Previously, graphene has already been used to create speakers, but in the past it was made from diffusers, which led to an increase in the efficiency of the device. From the new dynamics, all the moving parts disappeared, which allowed to reduce its size and increase its effectiveness. The speaker is made in the form factor of a microprocessor the size of a thumbnail. Inside the processor case, in addition to the speaker itself, the amplifier and even the graphic equalizer are hidden.

The thermoacoustic principle of operation allows you to convert the temperature into sound or vice versa – to convert sound vibrations into heat. This effect was first described at the end of the XIX century by the scientist Lord Rayleigh. In the middle of the twentieth century, interest in the interrelation between sound and heat greatly increased, since it was necessary to study the instability in combustion chambers with huge temperature differences. To date, there are thermoacoustic engines and even thermoacoustic refrigerators. But thermoacoustic speakers, and even from graphene, so far no one has created.

Graphene is an excellent conductor, therefore, by passing electrical impulses through it, you can quickly heat up and cool it. The grafen membrane expands and contracts, which affects the ambient air and generates sound waves. How good is the sound obtained in this way? The team of researchers claims that the graphene thermoacoustic speaker allows to get a “rich sound palette”, depending on how and where it is supplied with electricity. Heating and cooling cycles allow you to create multiple audio frequencies at the same time, while mixing them together, amplifying and tuning their sound. Scientists even managed to obtain ultrasound.

The results of research by British scientists were published in the journalScientific Reports.

Please follow and like us:

Graphene can solve the five biggest problems of the world

In September 2015, world leaders gathered at the historic UN summit to adopt sustainable development goals (SDG). Seventeen of these ambitious goals and indicators will help guide and coordinate governments and international organizations to solve global problems. For example, SDG 3 provides “ensuring a healthy lifestyle and affordable well-being for all people at any age”. Others include access to clean water, reducing the effects of climate change and affordable health care.

If you think that these goals are difficult to achieve, you are right. In all seventeen categories there are problems that will not allow them to happen before the designated date in 2030. However, in combination with progress in the socio-political arena, progress in science and technology can become a key accelerator of this process.

Let’s give all the goals of the SDG:

  1. The universal elimination of poverty in all its forms
  2. Eliminate hunger, ensure food security and improve nutrition and promote sustainable agricultural development
  3. Providing a healthy lifestyle and promoting well-being for all at any age
  4. Ensuring inclusive and equitable quality education and promoting lifelong learning opportunities for all
  5. Ensuring gender equality and empowering all women and girls
  6. Ensure availability and rational use of water resources and sanitation for all
  7. Ensuring access to affordable, reliable, sustainable and modern energy sources for all
  8. Promote sustained, inclusive and sustainable economic growth, full and productive employment and decent work for all
  9. Creating a strong infrastructure, promoting inclusive and sustainable industrialization and innovation
  10. Reducing the level of inequality within and between countries
  11. Ensuring the openness, security, resilience and sustainability of cities and human settlements
  12. Ensuring rational consumption and production patterns
  13. Adoption of urgent measures to combat climate change and its consequences
  14. Conservation and sustainable use of oceans, seas and marine resources for sustainable development
  15. Protection, restoration of terrestrial ecosystems and promotion of their rational use, rational management of forests, combating desertification, cessation and reversal of land degradation and cessation of loss of biological diversity
  16. Promoting the building of peace-loving and open societies for sustainable development, ensuring access to justice for all and creating effective, accountable and participatory institutions at all levels
  17. Strengthening the means for achieving sustainable development and strengthening the mechanisms of global partnership for sustainable development

Complicated? Maybe. But scientists seem to have an answer. Just one word: graphene. Futuristic material with a growing set of potential applications.

Graphene consists of densely connected carbon atoms lined up in a lattice one atom thick. This makes it the thinnest substance in the world, which is 200 times stronger than steel, flexible, stretchable, self-healing, transparent, conductive and even superconducting. A square meter of graphene weighing only 0.0077 grams can withstand four kilograms of the load. This is an amazing material, which, however, does not surprise scientists and technical experts.

Headlines that advertise graphene as a miracle material have appeared regularly over the past ten years, and the transition from promise to reality has been slightly delayed. But this is logical: it takes time for the new material to find itself in all spheres of life. Meanwhile, these years of graphene research have given us a long list of reasons not to forget about it.

Since graphene was first allocated in 2004 at the University of Manchester – and this work earned the Nobel Prize in 2010 – scientists around the world have found new ways of using and, importantly, creating graphene. One of the main factors restraining the widespread use of graphene was the large-scale production of cheap graphene. Fortunately, seven-league steps were taken in this direction.

Last year, for example, a group from the Kansas State University used explosions to synthesize large quantities of graphene. Its method is simple: fill the chamber with acetylene or ethylene and oxygen. Use the car’s spark plug to detonate. Collect the resulting graphene. Acetylene and ethylene consist of carbon and hydrogen, and when hydrogen is absorbed during the explosion, carbon freely binds to itself, forming graphene. This method is effective, because all that is required is one spark.

Whether this method can start the graphene revolution, as some believe, remains to be seen. What is obvious is that together with the onset of this revolution many problems will be solved. For example…

Pure water

The sixth objective outlined in the SDG is listed as “to ensure accessibility and sustainable water management and sanitation for all”. According to UN estimates, “the water deficit affects more than 40% of the world’s population and is projected to grow.”

Filters based on graphene could well be a solution. Jiro Abraham of the University of Manchester helped develop scalable sieves from graphene oxide to filter seawater. He argues that “the developed membranes are useful not only for desalination, but also for changing the pore size in atomic scales, allowing to filter ions according to their sizes.”

In addition, researchers from Monash University and the University of Kentucky have developed graphene filters that can filter out anything that is larger than one nanometer. They say that their filters can be used to filter chemicals, viruses or bacteria in liquids. They can be used to purify water, dairy products or wine, or to produce pharmaceuticals.

Carbon emissions

The thirteenth objective on the SDG list is devoted to the adoption of “urgent measures to combat climate change and its consequences”.

Of course, one of the main culprits of climate change is the excessive amount of carbon dioxide released into the atmosphere. Graphene membranes could catch these emissions.

Scientists from the University of South Carolina and Hanyang University in South Korea have independently developed graphene-based filters that can be used to separate unwanted gases from industrial, commercial and residential emissions. Henry Foley of the University of Missouri claimed that these discoveries had become “something of a holy Grail.”

With their help, the world could stop the growth of CO 2 in the atmosphere, especially now that we have overcome an important figure of 400 parts per million.

Health care

Many people around the world do not have access to adequate health care, but graphene can turn this issue upside down.

First of all, the high mechanical strength of graphene makes it an ideal material for the replacement of parts of the body such as bones, and due to its conductivity it can replace parts of the body that require electric current, for example, organs and nerves. In fact, scientists at the University of Michigan are working on the use of 3D printers for nerve printing based on graphene, and this team is developing biocompatible materials using graphene for electricity.

Graphene can also be used to create biomedical sensors for the detection of diseases, viruses and other toxins. Since every graphene atom is exposed to it – due to the fact that graphene is one atom thick, – the sensors can be extremely sensitive. Sensors based on graphene oxide could detect toxins at levels 10 times smaller than modern sensors require. They could be placed on or under the skin and provide doctors and scientists with a wealth of information.

Chinese scientists even created a sensor that can detect only one cancer cell. Moreover, scientists from Manchester University report that graphene oxide can find and neutralize cancer stem cells.


The ninth goal of the SDG is “to create a solid infrastructure, to promote inclusive and sustainable industrialization and innovation”. Composites reinforced with graphene, and other building materials can bring us closer to this goal.

Recent studies have shown that the more graphene is added, the better the composite becomes. This means that graphene can be added to building materials – concrete, aluminum, which will make them stronger and lighter.

Rubber is also improved by the addition of graphene. A study by Graphene Flagship and its partner Avanzare reports that “graphene enhances the functionality of rubber by combining the electrical conductivity of graphene and mechanical strength with excellent corrosion resistance.” Of such rubbers, it would be possible to make pipes that are more resistant to corrosion.


The seventh task is to provide access to low-cost, reliable, sustainable and modern energy sources for all. Because of the ease, conductivity and tensile strength, graphene can make green energy more efficient and cheaper.

For example, graphene composites could be used to create more versatile solar panels. Researchers at the Massachusetts Institute of Technology say that “with the help of graphene it is possible to make flexible, inexpensive and transparent solar cells that can turn almost any surface into a source of electricity.” Thanks to graphene composites, it is also possible to create large and light wind turbines.

In addition, graphene is already used to improve the traditional lithium-ion batteries, which are commonly used in consumer electronics. Studies of graphene airgels for storing energy and supercapacitors are also being conducted. All this will be needed for large-scale storage of clean energy.

Over the next ten years, graphene will almost certainly find many applications in the real world and will not only help the UN and its participants achieve SDG goals, but will also improve everything in our world, from touch screens to MRI devices and transistors.

Please follow and like us: