Content in part from WIRED
Carbon fiber is one of the strongest and most lightweight materials in existence. Its prevalence has steadily grown in the past 10 years – it’s been used in everything from stunt planes to racing drones to SpaceX rockets. Many of the 100+ VTOL companies in development companies utilize carbon fiber in their designs.
Carbon fiber mainly consists of carbon atoms, bonded together with crystals. Strips of fiber that contain these atoms are then woven together into a sheet or fabric, which can be used for civil engineering, aerospace, and more. What makes carbon advantageous over other materials is its low weight and high tensile strength.
Carbon fiber has been used in the aerospace industry for years, replacing aluminum on aircraft like the Airbus A350 XWB and the Boeing 787 Dreamliner. It’s also been used in bicycles and Formula One cars, making it an ideal material for eVTOL Air Taxis. In fact, carbon fiber may be absolutely crucial to these designs, since many of them seek total or partial use of electric power. In an industry where battery technology is still evolving, designers and engineers are doing everything possible to reduce the amount of power these aircraft require to fly.
However, carbon fiber is expensive and difficult to fabricate. The process includes laying up resin-soaked carbon-fiber sheets in molds, trimming the pieces after they’ve cured in an oven, and then bonding components together. This process can take many hours and requires complex equipment. This may not mean much for aircraft like the Airbus A350 XWB and the Boeing 787 Dreamliner which are produced in relatively low volumes, but the demand for urban air taxis may be for many thousands of vehicles.
Companies from big to small recognize this problem and are trying to address it. According to Scott Drennan (vice president of innovation at Bell) including manufacturing teams in the design process is a critical component of success with composites. If the aircraft is not designed with consideration to whether or not it can be feasibly built, a great deal of time and energy is wasted rethinking tooling.
There are a number of emerging companies that employ dedicated carbon fiber fabrication processed. Among these are Game Composites, founded by Stuart Walton, which builds and sells light sports aircraft with using a myriad of carbon fiber parts. Also mentionable is recently founded Elevated Materials, which upcycles carbon fiber from the space industry, as well as North Carolina-based Blue Force Technologies, which has partnered with Beta Technologies.
Why it’s important: As the VTOL industry grows and demand for carbon fiber continues to increase, the process for mass producing these composites must evolve. While producing carbon fiber may currently be expensive and time-consuming, companies focused on making the production process more efficient are already emerging. Carbon fiber is a hurdle for the mass-production of air taxis, but also presents the opportunity for yet another innovative practice in an innovative industry.