VOA慢速英语2015 21世纪的新材料—石墨烯（在线收听）

Graphene: The Material of the 21st Century 21世纪的新材料—石墨烯

Graphene is a type of graphite mineral. Experts often call it 'The Material of the 21st Century' because of its special properties. Some U.S. companies are already using graphene for new technology products.

Graphene is often described as a one-atom-thick layer of carbon. The material has some extraordinary properties. It is 100 times stronger than steel of the same thickness. The nearly transparent material also carries heat and electricity very well.

Dan Scheffer is vice-president of the manufacturing company, Vorbeck Materials.

"This material has so many potential applications that you don't know where to start to look in the beginning."

Mr. Scheffer says 100 percent pure graphene is difficult to make. But he adds manufacturers can make graphene of lesser purity that still has many of the features of the pure version. Mr. Scheffer says his company produces a layer of graphene that is 80 percent pure.

Graphene can be mixed into ink for printers. Stretchable parts can be printed for products such as antennas for radio frequency identification circuits.

Louise Brooks is the manager of the product development team at Vorbeck Materials. She says graphene can even be used on wearable electronic clothing. She says the clothing can be washed and dried in a machine without damaging the graphene.

The new material can also be used to make very sensitive microphones. Ray Sauro is a chemical engineer at Vorbeck Materials. He says a graphene membrane less than one micron thick can pick up vibrations that no other kind of membrane can.

"And, it has a working range of less than one hertz to 200,000 hertz. The human ear for example can hear from about 15 hertz to 20,000 hertz.  So, way beyond anything you can hear."

The microphone picks up the sound from light that reflects off a vibrating graphene membrane. This prevents any radio or magnetic interference.

Mr. Sauro says graphene membranes can resist vibrations and heat. He adds that the membranes are not costly to manufacture.  Mr. Sauro imagines the automotive industry will be able to use graphene products in vehicles to collect information about engine health.  He says such products would not cost more than $300. 

Words in This Story

antenna – n. a device (such as a wire or a metal rod) for sending or receiving radio or television signals

circuit – n. the complete path that an electric current travels along

hertz – n. a unit used for measuring the frequency of sound waves

membrane – n.  a thin sheet or layer

microphone – n. a device used to record sound