Graphene Audio - Page 4

Researchers from the University of Exeter developed a new chip that combines a thermoacoustics graphene-based speaker, amplifier and graphic equalizer. A thermoacoustics speaker creates sounds by heating and cooling the thin graphene membrane rapidly by an alternating electric current - and the transfer of the thermal variation to the air causes it to expand and contract, thereby generating sound waves.

Thermoaccoustic speakers based on graphene has been demonstrated before, but the Exeter researchers are the first to embed such a speaker, an amplifier and a graphic equalizer on a millimetre-sized device. The researchers see possible applications in ultrasound imaging, telecommunication and maybe even intelligent bandages that monitor and treat patients directly.

Apple was granted a new patent (filed in 2015) that details an audio device that uses a diaphragm made from a graphene-enhanced composite material. Apple's graphene membrane can be used in a speaker, microphone or headphone device. The patent specifically includes an image of an iPhone device as an example application.

Apple explains that as devices become smaller and lighter, it is ever more challenging to provide high quality audio using conventional materials - and graphene may improve the mechanical response of the audio device. In addition, in some cases, the use of graphene or graphene flake materials may reduce or eliminate the need for additional external damping.

China-based FiiO Electronics launched new in-ear monitor earphones, the FiiO F3, that make use of a graphene-enhanced diaphragm driver. FiiO says that graphene enabled the development of a thin and flexible driver, which enables the F3 to faithfully reproduce music with a clean, rich, yet transparent high-fidelity sound.

The FiiO F3 is now shipping in China and in the US, you can buy one at Amazon.com now for $24.99. We talked to FiiO and they confirm the graphene membrane and explained that it was not developed by FiiO in-house. You can see a close-up of the graphene driver below.

Wuxi JCNO Materials, a company located in the Wuxi Graphene Industry Zone in China, has created a graphene-based electrostatic speaker. The speakers are reportedly constructed using graphene resin composite materials, able to produce medium and low bass sounds that conventional metal resin compounds cannot reach. The graphene speaker is also said to be simpler, longer-lasting and cheaper to produce than traditional technology.

Electrostatic speakers sound by vibrating the diaphragm before and after with the action of electrostatic force. It can capture the extremely small changes in the music signal to fully show the nuances of the music. This kind of speaker has already been used in applications like cars, theaters and exhibitions.

ORA, a Canada-based early-stage start-up that develops graphene-enhanced audio equipment, has unveiled its graphene oxide-based composite material, dubbed grapheneQ. The material was thus named because of its low density and high stiffness, that reportedly allow for louder drivers that have a lower Q resonance, and has been specially designed for use in acoustic transducers.

Loudspeakers work by vibrating a thin diaphragm. These vibrations then create pressure waves in surrounding air that produce different sounds depending on their frequency. The membrane in any speaker can be thought of as a simple harmonic oscillator with an intrinsic mass and restoring force. The heavier the membrane’s mass, the more inertia and sharper resonance it has because of its high Q. The most common way to reduce resonance and broaden bandwidth is to add damping, but this ultimately reduces the efficiency of the driver.

Israeli audio pioneer Waves Audio is going to develop an innovative electrostatic speaker using a nanoscale active membrane based on graphene in collaboration with the Virginia Polytechnic Institute and State University.

The new speaker will hopefully achieve significant energy savings, and so Waves and the Virginia Polytechnic recieved funding from the US Department of Energy (DOE) and Israel's Ministry of National Infrastructure. The funding was part of the BIRD Energy program. This was one of five projects that were together received $4 million funding.

The Chinese mobile phone maker Xiaomi recently launched a new in-ear headphones, called ‘Piston 3 Pro’, that according to reports from various websites and blogs makes use of a ‘graphene diaphragm’ that helps in producing more natural sounds. The use of graphene, however, was not mentioned in the Xiaomi official website.

We are quite skeptical about the presence of an actual graphene membrane that enhances the sound quality in this product; It seems possible that Xiaomi is using some form of graphene added to the product but we will wait to find a more formal explanation as to what its role actually is, if any.

Researchers at Korea Advanced Institute of Science and Technology (KAIST) have developed a new graphene oxide-based speaker design said to be specifically targeted for the mobile audio market. The speaker does not require an acoustic box to produce sound.

The researchers used graphene in a relatively simple, two-step process that yielded a thermoacoustic speaker. Thermoacoustics is based on the idea that sound can be produced by the rapid heating and cooling of a material instead of through vibrations.

Researchers at the University of California, Berkeley, used graphene to build lightweight wireless ultrasonic loudspeakers and microphones. These devices complement standard radio transmission using electromagnetic waves in areas where radio is impractical, such as underwater, but with far greater fidelity than current ultrasound or sonar devices. They can also be used to communicate through objects, such as steel, that electromagnetic waves can’t penetrate.

Speakers and microphones both use diaphragms, typically made of paper or plastic, that vibrate to produce or detect sound. The diaphragms in the new devices are graphene sheets that have the right combination of stiffness, strength and light weight to respond to frequencies ranging from subsonic (below 20 hertz) to ultrasonic (above 20 kilohertz). Graphene is thin enough to respond immediately to pulses, and is very light so it is able to generate sharp pulses and measure distance much more accurately than traditional methods. The human hearing range is from 20 hertz up to 20,000 hertz, whereas bats hear only in the kilohertz range, from 9 to 200 kilohertz. The grapheme loudspeakers and microphones operate from well below 20 hertz to over 500 kilohertz.

An American company called Cerious Technologies is now offering several types of graphene-based cables and interconnects for sale. Cerious is focused on manufacturing and selling audio products like speakers, sound systems and various audio cables and interconnects.

Cerious' Graphene Extreme is an interconnect cable that utilizes graphene (which Cerious states is of its own manufacture) as a conductor technology. The company says that the ultra fine conductor enables the cable to operate linearly well into the gigahertz while being non-magnetic. This eliminates ringing and the bounce that occurs from normal terminations. It offers deeper soundstage, more detail and quieter backgrounds.