Acoustic Fabric

Having trouble hearing? Just turn up your shirt. That’s the idea behind a new “acoustic fabric” developed by engineers at MIT and collaborators at Rhode Island School of DesignThe team has designed a fabric that works like a microphone, converting sound first into mechanical vibrations, then into electrical signals, similarly to how our ears hearAll fabrics vibrate in response to audible sounds, though these vibrations are on the scale of nanometers — far too small to ordinarily be sensed. To capture these imperceptible signals, the researchers created a flexible fiber that, when woven into a fabric, bends with the fabric like seaweed on the ocean’s surface.

The fiber is designed from a “piezoelectric” material that produces an electrical signal when bent or mechanically deformed, providing a means for the fabric to convert sound vibrations into electrical signalsThe fabric can capture sounds ranging in decibel from a quiet library to heavy road traffic, and determine the precise direction of sudden sounds like handclaps. When woven into a shirt’s lining, the fabric can detect a wearer’s subtle heartbeat features. The fibers can also be made to generate sound, such as a recording of spoken words, that another fabric can detectA study detailing the team’s design appears in Nature. Lead author Wei Yan, who helped develop the fiber as an MIT postdoc, sees many uses for fabrics that hear.

Wearing an acoustic garment, you might talk through it to answer phone calls and communicate with others,” says Yan, who is now an assistant professor at the Nanyang Technological University in Singapore. “In addition, this fabric can imperceptibly interface with the human skin, enabling wearers to monitor their heart and respiratory condition in a comfortable, continuous, real-time, and long-term manner.”

Yan’s co-authors include Grace Noel, Gabriel Loke, Tural Khudiyev, Juliette Marion, Juliana Cherston, Atharva Sahasrabudhe, Joao Wilbert, Irmandy Wicaksono, and professors John Joannopoulos and Yoel Fink at MIT, along with collaborators from the Rhode Island School of Design (RISD), Lei Zhu from Case Western Reserve University, Chu Ma from the University of Wisconsin at Madison, and Reed Hoyt of the U.S. Army Research Institute of Environmental Medicine.

Source: https://news.mit.edu/

Plant Viruses Used to Ward Off Pests

Imagine a technology that could target pesticides to treat specific spots deep within the soil, making them more effective at controlling infestations while limiting their toxicity to the environment.

Researchers at the University of California San Diego and Case Western Reserve University have taken a step toward that goal. They discovered that a biological nanoparticle—a plant virus—is capable of delivering pesticide molecules deeper below the ground, to places that are normally beyond their reach.

The work could help farmers better manage difficult pests, like parasitic nematodes that wreak havoc on plant roots deep in the soil, with less pesticide. The work is published May 20 in the journal Nature Nanotechnology.

It sounds counterintuitive that we can use a plant virus to treat plant health,” said Nicole Steinmetz, a professor of nanoengineering at the UC San Diego Jacobs School of Engineering and senior author of the study. “This is an emerging field of research in nanotechnology showing that we can use plant viruses as pesticide delivery systems. It’s similar to how we’re using nanoparticles in medicine to target drugs towards sites of disease and reduce their side effects in patients.

Pesticides are very sticky molecules when applied in the field, Steinmetz explained. They bind strongly to organic matter in the soil, making it difficult to get enough to penetrate deep down into the root level where pests like nematodes reside and cause damage. To compensate, farmers end up applying large amounts of pesticides, which cause harmful residues to build up in the soil and leach into groundwater.

Steinmetz and her team are working to address this problem. In a new study, they discovered that a particular plant virus, Tobacco mild green mosaic virus, can transport small amounts of pesticide deep through the soil with ease.

Source: https://ucsdnews.ucsd.edu/