Federal Researchers Create 'Second Skin' to Shield Against Biological Threats

A Lawrence Livermore National Laboratory-led team of scientists has developed a breathable, protective smart fabric—deemed a “second skin”—that’s designed to shield wearers by responding, itself, to chemical and biological agents.

Researchers from the California-based lab, together with collaborators from the Massachusetts Institute of Technology and U.S. Army Combat Capabilities Development Command recently completed the first phase of a project to create the cutting-edge material, which can autonomously react to microscopic dangers in its environment and might offer a glimpse into the future of smart uniforms worn by the military, first responders and more. 

“Combining breathability and protection in the same garment is very challenging, but key for their safe, extended use,” Francesco Fornasiero, the LLNL scientist leading the team told Nextgov Friday, detailing the inspiration behind the effort. 

As the novel coronavirus pandemic has demonstrated and amplified, military and other federal officials at times must expose themselves to toxic or contaminated environments and confront biological threats like viruses and bacteria or even smaller, chemical agents like sarin gas, firsthand. In those efforts, officials depend on the proper protective equipment to ensure their safety, however as Fornasiero indicated, standard protective fabrics’ makeup and absorbent layers inhibit breathability, or “the transfer of water vapor from the wearer’s body to the outside world.” 

The lab’s effort is funded by the Defense Threat Reduction Agency’s Dynamic Multifunctional Materials for a Second Skin—or D[MS]2—program, which seeks to promote the technological development of next-generation clothing that provides military officials with robust protection from chemical and biological threats, while also offering wearers a level of comfort akin to being in their own skin. Over the last six or so years, Fornasiero and the team worked to create and refine their multifunctional material through the first phase of the program, which they recently completed and subsequently published details about in the scientific journal Advanced Functional Materials.

The base layer of their developed, smart fabric comprises trillions of aligned carbon nanotube pores, which according to the lab’s release of the work, are “graphitic cylinders with diameters more than 5,000 times smaller than a human hair.” The nanotubes are equipped to transport water molecules through their interior, thus ensuring necessary breathability, and they are also small enough to block biological threats. Grafted or “grown” onto that layer, is a threat-responsive polymer layer that can protect against the even tinier chemical threats that can fit through the nanotubes’ pores. Considered the “smart” layer, this dynamic chain of polymers can reversibly collapse when the wearer comes into contact with any risky chemical hazards.

“The response of the material is autonomous and local. It is triggered by the contact of the chemical threat with the polymers on the surface of the membrane,” Fornasiero explained. “The polymer chains are normally extended (or open state), but when the chemical threat reaches the material surface, the polymer chains stack together and collapse, leading to pore closure and limiting permeation of the threat across the membrane.”

Meeting the initial project requirements to balance comfort and defense within the same garment, the team is moving on to the next phase, which will involve producing even further protection against more chemical threats—and making the material more stretchable, “for a better body fit, thus more closely mimicking the human skin,” the release states. Fornasiero noted those next steps will likely occur over three years. On top of that, he said full deployment of such a smart uniform, which would be suited for work across warzones and clinical and medical settings, may take an additional five or more years. 

The “best case scenario” outcome of the efforts, in his eyes, would be the fruition of protective military garments that are very breathable—“and thus so comfortable”—they can be worn all the time.

“This would eliminate the problem of changing gears when you may be entering a contaminated area, as well as enable use for long operations without risking heat stress or stroke,” Fornasiero said. “Also, since the protection is autonomous, a wearer would be protected even in situations where he is unaware of the presence of a threat.”