Vegan mists can be used in N95 masks and power devices

Rutgers University

Engineers have devised a method for spraying extremely thin wires on 3D objects

Image (left) of a nanowire forest sprayed onto a miniature tree, with color (purple) originating from the embedded gold nanoparticles. Electron microscope image (right) of the nanowire / nanoparticle combination. Photos: (left) Jonathan B. Singer; (Right) Lin Li

Engineers have devised a method for spraying ultra-thin wires made of plant material that could be used in N95 mask filters, devices that collect energy for electricity, and possibly create human organs.

The method involves spraying methylcellulose, a renewable plastic derived from vegetable cellulose, on 3D-printed objects and other things ranging from electronics to plants, according to a study led by Rutgers in the journal Materials Horizons.

“This could be the first step toward 3D fabricating organs with the same kinds of amazing properties as those we see in nature,” said lead author Jonathan P. Singer, assistant professor in the Department of Mechanical and Aerospace Engineering at the School of Engineering. At Rutgers University – New Brunswick. In the near term, there is demand for N95 masks as personal protective equipment during the COVID-19 pandemic, and our spray method could add another level of capture to make the filters more effective. Electronics such as LED lights and power harvesters can also benefit.

Thin wires (nanowires) made from a soft material have many applications, including the cilia that keep our lungs clean and the rough structures that allow geckos to grip onto the walls. These wires have also been used in small monopoly electric power harvesters, with future examples likely to include shoe-wrapped chips for charging a cell phone and a door handle sensor that triggers the alarm.

While people have known how to make nanowires since the advent of deer melt cotton candy, control over the process has always been limited. The barrier was the inability to spray these wires rather than spin them.

The Singer Hybrid Micro / Nanomanufacturing Laboratory, in collaboration with engineers at Binghamton University, revealed the basic physics for creating such nebulizers. Using methylcellulose, they created “forests” and foams of nanowires that can be covered on 3D objects. They also showed that gold nanoparticles can be embedded in wires for optical sensing and staining.

The lead author is Lin Lee, a PhD student at Rutgers University. Catherine J. Nachtigal, an undergraduate at Rutgers University, is in the study.