In this issue of Manufacturing Ideas to Watch: High-Strength Composites, Carbon Nanotube-Based Sensing Composites, Non-destructive Evaluation, Wood Stronger Than Titanium, and Efficient Ammonia Production. Let us know what you think by leaving a comment!
Additive Manufacturing of High-Strength Composites
Researchers at Kansas State University have developed a method to additively manufacture composites with comparable strength to those made using traditional manufacturing methods, such as compression molding. The novel process uses a laser to bond and cut layers of fiber prepreg or tape to create 3D parts from continuous fiber reinforced thermoplastic composites. The resulting parts have 300% better strength than additive manufactured composites produced with fused deposition modeling. This process has applications in automotive, aerospace, marine, and other industries that will benefit from traditional composite properties with the versatility of additive manufacturing.
– Dong Lin, Kansas State University
Carbon Nanotube-Based Sensing Composites
Structural health monitoring to measure the status of civil structures and buildings is critical to maintaining a robust infrastructure. Existing methods face challenges in obtaining real-time distributed measurements, especially at scales small enough to detect micro-cracks that lead to eventual failure. Researchers have developed a method to create a nanotube composite that couples axial strain of the material to a large change in electrical resistance. Electrical tunneling gaps between the carbon nanotubes increase as the material is strained. The carbon nanotubes are coated onto a carrier fabric to form the conductive network, and epoxy can then be added to form a stand-alone sensing “Smart Veil” with versatile applications. This “Smart Veil” can also be applied to polymer composites, enabling continuous feedback during processing.
– Erik T. Thostenson, University of Delaware and Thomas Schumacher, Portland State University
Novel Non-destructive Evaluation
Fatigue failure of aerospace parts can have disastrous results, as the recent accident of Southwest flight 1380 illustrates. Tools for identifying and studying fatigue cracking include acoustic emission, passive thermography, digital image correlation, and fiber optic sensors, but each of these methods has critical limitations. A team of researchers at NASA Langley Research Center developed a method that combines thermal and acoustic emission data to provide a much more sensitive evaluation tool than each alone. It can track multiple damage sites and identify false indications. The technique is applicable over large areas and for complex in-service parts.
– Joseph Zalameda, NASA Langley Research Center
Wood Stronger Than Titanium
Researchers at the University of Maryland at College Park discovered a method to make natural wood 10x stronger by simply removing the lignin and hemicellulose, and pressing the resulting cellulose body. The resulting material has a specific strength (strength per unit mass) stronger than titanium. Ballistic testing also illustrates the resilience of the material to impact. The two-step process uses common chemicals and takes place at relatively low temperature. Using softwoods (like pine or balsa) gives similar properties as slower-growing wood, offering an additional environmental advantage.
– Liangbing Hu, University of Maryland
Physical Catalysts Offer Pathway to Efficient Ammonia Production
Ammonia production is essential for fertilizer production, yet it accounts for 3% of the world’s energy use and contributes over 3% of greenhouse gas emissions worldwide. Researchers at Oak Ridge National Laboratory are developing a novel physical catalysts with promise to improve ammonia production. Unlike typical chemical catalysts, this physical catalyst uses spikes 50-80 nanometers high to amplify an electric field to a very strong 10 volts per nanometer. This enables the chemical reactions to take place without a chemical bond to the catalyst. Refining and scaling this method to industrial scale could provide a viable pathway to improved ammonia production.
– Adam Rondinone, Oak Ridge National Laboratory
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