The Happiest Materials Scientist

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

According to his NASA biography, “Dr. Ajay Misra, a member of the Senior Executive Service, is Chief of the Structures and Materials Division in the Research & Technology Directorate at the NASA Glenn Research Center in Cleveland, Ohio.  In this position, Dr. Misra has the responsibility for planning, advocating, coordinating, organizing, directing and supervising all phases of Division research and business activities.” 

At the fourth annual Electric Aircraft Symposium in Rohnert Park, California in April 2010, Dr. Misra was among the most charming and happiest of presenters – probably because he had so many happy things to talk about. 

Much of the joy comes from the continuing revelations about the characteristics of carbon and boron nanotubes.  They turn out to be absolutely wonderful for thermal, structural, battery, capacitor and motor applications.  Dr. Misra’s talk sounded at times like a pitch for a wonder cure-all, but one backed with solid scientific precepts.

Nanotube-reinforced-ultra-high-strength-composite

Boron nitrate nanotubes have better high-temperature characteristics than carbon equivalents, but are not yet generally available in long form, restricting their practical use at this time. 

In the near term, nanotubes can provide localized reinforcement in fiber matrixes while improving interlamination properties, such as reducing fractures at stress points.  NTs can reduce the weight of motor components while improving thermal characteristics increasing conductivity and providing an overall improved motor design with reduced parts count.

For energy storage, mixing carbon and boron NTs in capacitors increases both energy and power density while reducing weight. Crafting solid oxide fuel cells from nanotube reinforced, engineered ceramic microstructures produces lighter units with better hydrogen production characteristics and eliminates the use of expensive platinum catalysts.  Clay nanocomposites themselves can reduce micro-cracking and permeability for such devices.

Structures benefit from such materials.  Fiber-reinforced foam (FRF) cores as part of sandwich panels can produce the multifunctional structures that promise so much for future flight.  As noted in this blog, such panels have the ability to collecting sunlight for power, store the resulting electrical energy, and still meet the structural requirements of a craft.  Think, for instance, of the weight, structural, and energy collection storage capabilities of an FRF panel reinforced with graphene facings – then power that structure with a nanotube enhanced motor.  Unifying all functions within a simple structure could bring about a true revolution in aircraft design, construction, and power.

As a side note, a paper in Nanoscale, a peer-reviewed journal from the Royal Society of Chemistry, enumerates over 12,000 scientific papers on carbon nanotubes published in 2009 alone, and only about 300 on boron nanotubes.  This disparity points to the relative accessibility to carbon materials and the ease with which many laboratories can produce their own samples.

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