World's lightest solid material, known as 'frozen smoke', gets even lighter

Researchers have created a new aerogel that boasts amazing strength and an incredibly large surface area. Nicknamed ‘frozen smoke’ due to its translucent appearance, aerogels are manufactured materials derived from a gel in which the liquid component of the gel has been replaced with a gas, resulting in a material renowned as the world’s lightest solid material. The new so-called “multiwalled carbon nanotube (MCNT) aerogel” could be used in sensors to detect pollutants and toxic substances, chemical reactors, and electronics components.

Although aerogels have been fabricated from silica, metal oxides, polymers, and carbon-based materials and are already used in thermal insulation in windows and buildings, tennis racquets, sponges to clean up oil spills, and other products, few scientists have succeeded in making aerogels from carbon nanotubes.

The researchers were able to succeed where so many before them had failed using a wet gel of well-dispersed pristine MWCNTs. After removing the liquid component from the MWCNT wet gel, they were able to create the lightest ever free-standing MWCNT aerogel monolith with a density of 4 mg/cm3.

MWCNT aerogels infused with a plastic material are flexible, like a spring that can be stretched thousands of times, and if the nanotubes in a one-ounce cube were unraveled and placed side-to-side and end-to-end, they would carpet three football fields. The MWCNT aerogels are also excellent conductors of electricity, which is what makes them ideal for sensing applications and offers great potential for their use in electronics components.

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Endless Forms Web Site Helps Users 'Breed' 3-D Printable Objects

Forget draft tables and complicated computer-aided design programs: You dream it. Endless Forms helps you design it.

Cornell University engineers are allowing anyone to point, click, collaborate and create online in the evolution of printable, three-dimensional objects. They aim to transform the design of art, architecture and artificial intelligence.

Their new, interactive websiteEndlessForms.com, allows users to design their own things -- from lamps and butterflies to furniture and faces -- without any technical knowledge and using the same principles that guide evolutionary biology.

The Web site was developed by Jeff Clune, Cornell postdoctoral fellow; Jason Yosinski, Cornell graduate student in engineering; and Eugene Doan, Cornell undergraduate student in the Creative Machines lab of Hod Lipson, Cornell associate professor of mechanical and aerospace engineering and computing and information science.

EndlessForms users can develop objects just as gardeners raise roses -- a "generation" of objects is displayed, and a user chooses objects they like, which are "bred" to produce the next generation. Over time, objects evolve and users can publish these objects. Others can further evolve, share and rate them, creating a collaborative exploration of designs that, according to Lipson, represents an entirely new way of thinking about design. Users can then have their objects made by 3-D printing companies in a wide range of materials, such as silver, steel, ceramic or sandstone.

The concept eliminates the need for skilled engineers to draw in Computer-Aided Design (CAD) programs, which can be complicated and non-intuitive. These new design tools free people to focus creativity, instead of being mired in technical details, Lipson said.

Now that 3-D printing is taking off, the goal is to unshackle the design process, flooding the industry with objects that are truly one of a kind. Lipson likens the 3-D printing industry to iPods with no music -- the printers exist, but the availability of content is bottlenecked by the old methods like CAD that few people know how to use and that stifle creativity.

The Web site demonstrates in real time the power of evolution to produce complex designs, providing a rare glimpse of the process in action. Users can also view the ancestral lineage of each object stretching back to the first, simple, randomly-generated object, and thus can see how evolution builds complexity via a series of small changes.

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