We could see a new Apple-signed, carbon fiber product; the company is at least preparing something using this material. This new rumor was started by the Japanese Macotakara blog, which has a good track record of reliable information.
The details come from an anonymous source who said Apple has requested carbon fiber samples from a company based in Japan that began production of the material in March. Foxconn and Apple spotted the unnamed company and placed an order for carbon fiber parts which seem to be too large to be samples, the source told Macotakara.
This may come as news, but Apple has shown interest in carbon fiber in earlier patent filings. One of these is related to housings and was made public in September.
In a much earlier filing, Apple considered lighter materials and a new construction method for portable devices. The patent reveals that in today's market most portable devices have plastic housings, which are relatively inexpensive and don't involve complex manufacturing processes. The problem is that they crack under relatively low stresses. Metal is good – it's more durable – but its weight and expensive manufacturing processes influence business decisions. An alternative described in the patent is CFRP, or carbon fiber reinforced plastic, which is made of multiple layers, each having carbon fibers aligned in a plastic matrix and suggests a sandwich construction solution for future portable devices.
In another filing -- 2010 -- Apple detailed how implementing carbon fiber would make the iPad lighter and stronger, with illustrations showing an iPad-like rear shell made of carbon fiber.
Currently, Apple uses aluminum for its iOS devices: the iPad's rear shell, and the recently released iPhone 5 both have aluminum backs, although the iPhone 4 and 4S having backs made of glass.