HomeNewsArticle Display

Air Force scientists discover unique stretchable conductor

The Air Force Research Laboratory developed Polymerized Liquid Metal Network rupturing to transform into a highly stretchable design that autonomously increases conductivity with strain. (Courtesy Image/Second Bay Studios.)

An illustration shows Polymerized Liquid Metal Network, developed by the Air Force Research Laboratory, rupturing to transform into a highly stretchable design that autonomously increases conductivity with strain. (U.S. Air Force courtesy graphic by Second Bay Studios)

WRIGHT-PATTERSON AIR FORCE BASE, Ohio (AFNS) --

The Air Force Research Laboratory has developed liquid metal systems which autonomously change structure so that they become better conductors in response to strain.

Conductive materials change their properties as they are strained or stretched. Typically, electrical conductivity decreases and resistance increases with stretching.

The material recently developed by AFRL scientists, called Polymerized Liquid Metal Networks, does just the opposite. These liquid-metal networks can be strained up to 700%, autonomously respond to that strain to keep the resistance between those two states virtually the same and still return to their original state. It is all due to the self-organized nanostructure within the material that performs these responses automatically.

“This response to stretching is the exact opposite of what you would expect,” Dr. Christopher Tabor, AFRL lead research scientist on the project said. “Typically a material will increase in resistance as it is stretched simply because the current has to pass through more material. Experimenting with these liquid-metal systems and seeing the opposite response was completely unexpected and frankly unbelievable until we understood what was going on.”

Wires maintaining their properties under these different kinds of mechanical conditions have many applications, such as next-generation wearable electronics. For instance, the material could be integrated into a long-sleeve garment and used for transferring power through the shirt and across the body in a way that bending an elbow or rotating a shoulder won’t change the power transferred.

AFRL researchers also evaluated the material’s heating properties in a form factor resembling a heated glove. They measured thermal response with sustained finger movement and retained a nearly constant temperature with a constant applied voltage, unlike current state-of-the-art stretchable heaters that lose substantial thermal power generation when strained due to the resistance changes. These properties and the material fabrication details are directly compared in the current issue of Advanced Materials at https://doi.org/10.1002/adma.201903864.

This project started within the last year and was developed in AFRL with fundamental research dollars from the Air Force Office of Scientific Research. It is currently being explored for further development in partnership with both private companies and universities. Working with companies on cooperative research is beneficial because they take early systems that function well in the lab and optimize them for potential scale up. In this case, they will enable integration of these materials into textiles that can serve to monitor and augment human performance.

The researchers start with individual particles of liquid metal enclosed in a shell, which resembles a water balloon. Each particle is then chemically tethered to the next one through a polymerization process, akin to adding links into a chain; in that way, all of the particles are connected to each other.

As the connected liquid metal particles are strained, the particles tear open and liquid metal spills out. Connections form to give the system both conductivity and inherent stretchability. During each stretching cycle after the first, the conductivity increases and returns back to normal. To top it off, there is no detection of fatigue after 10,000 cycles.

“The discovery of Polymerized Liquid Metal Networks is ideal for stretchable power delivery, sensing and circuitry,” said Capt. Carl Thrasher, AFRL Materials and Manufacturing Directorate research chemist and lead author on the journal article. “Human interfacing systems will be able to operate continuously, weigh less and deliver more power with this technology.”

“We think this is really exciting for a multitude of applications,” he added. “This is something that isn’t available on the market today so we are really excited to introduce this to the world and spread the word.”

Engage

Twitter
Twitter
RT @USAFReserve: Maintaining resiliency in paradise - https://t.co/IXktGzGgWc (Story by the @624RSG) #ReserveResilient https://t.co/ta8mMTP…
Twitter
RT @hack_a_sat: Tune in at 11 AM PDT to watch the LIVE closing ceremony with Dr. Will Roper and @bjgol. 🚀It's all happening at https://t.c…
Twitter
Difficult, but not impossible. @GenCQBrownJr addresses the challenges the Air Force faces going forward. https://t.co/kF4FdxN5S6
Twitter
“I want to show people the power of having faith & sticking to what you say you’re going to do.” - Staff Sgt. Gerem… https://t.co/524l6BUsyI
Twitter
What operates 24/7 ensuring the safety of aircraft & aircrews, AND provides prompt service to whoever is flying?… https://t.co/JMaYsTV5XH
Twitter
.@GenCQBrownJr explains what the Air Force can expect from his leadership: https://t.co/bxeqgZ1NSi
Twitter
RT @AirmanMagazine: Your daily @usairforce news! ✅ @Team_Tinker Airmen are using 3D printing to manufacture metal components successfully…
Twitter
5-year-old Wilder Umbarger, who suffers from X-Linked Adrenoleukodystrophy, wished he could see a real plane and me… https://t.co/nUtEk9e0u4
Twitter
.@GenCQBrownJr assumed his new role as Air Force Chief of Staff Aug. 6. https://t.co/kk8y15fOYe
Twitter
RT @AirNatlGuard: "Their exceptional service in conducting over 100,000 COVID tests set the conditions to reduce the effects of this pandem…
Twitter
Botinsol Analytics has developed a portable precision chem-bio lab for people who need to do real-time analysis in… https://t.co/XgOq8ROkSE
Twitter
#FollowFriday: The 22nd Air Force Chief of Staff @GenCQBrownJr https://t.co/UOG0JDKTVJ
Twitter
RT @GenCQBrownJr: On #PurpleHeartDay we honor and remember the members of the U.S. Armed Forces who were wounded in combat or paid the ulti…
Twitter
.@GenDaveGoldfein retired from active duty and passed on the duty of Air Force Chief of Staff to @GenCQBrownJr. https://t.co/AdlykogVjZ
Twitter
.@GenCQBrownJr's tenets of leadership: - Execute at a high standard - Be disciplined in execution - Pay attention… https://t.co/9EmCYue0OO
Twitter
RT @AirMobilityCmd: We are incredibly proud of our #TotalForce #MobilityAirmen and their support to ongoing relief efforts in #Lebanon. Del…
Twitter
Today, we salute the #heroes, wounded or killed in action, who have served our country. #PurpleHeartDay https://t.co/4yHljdUaNf
Twitter
RT @GenCQBrownJr: I’m blessed to have Sharene by my side & the support of our sons, Sean & Ross. She has committed so much to our family &…
Twitter
RT @CENTCOM: Gen McKenzie informed Gen Aoun of the impending delivery of three C-17s shipments of U.S. relief supplies including food, wate…
Facebook
The newest Air Force Podcast recently dropped. Listen to a small snippet of CMSAF Kaleth O. Wright talk with Staff Sgt. New about resiliency. Listen to the entire podcast on Youtube: https://go.usa.gov/xpnAD or Subscribe to The Air Force Podcast on iTunes: https://podcasts.apple.com/podcast/the-air-force-podcast/id1264107694?mt=2
Facebook
Our mantra, "Always ready!" It's the spirit we fly by! #B2Tuesday
Facebook
Need some motivation to get your week started off right? Listen as CMSAF Kaleth O. Wright weighs in...
Facebook
The U.S. Air Force Academy gives its cadets some unique opportunities. Ride along one of this opportunities.
Facebook
A United States Air Force KC-135 Stratotanker refuels an F-22 Raptor over northern Iraq, Nov. 6, 2019. U.S. Central Command operations deter adversaries and demonstrate support for allies and partners in the region. (Video by Staff Sgt. Daniel Snider)
Facebook
Although the Silver Star is the third-highest military medal, it's not given often. Today, TSgt Cody Smith was the 49th Special Tactics Airman to receive this medal since Sept. 11th, 2001. Read more of TSgt Smith's amazing story: https://www.airforcespecialtactics.af.mil/News/Article-Display/Article/2024815/special-tactics-airman-battled-through-injuries-awarded-silver-star/fbclid/IwAR2LZWwx1VHdTnQe39rIEBOuJS_0JvMQBBGt7I-E6zsxxn-Lx9387yu43Bc/ Cannon Air Force Base Air Force Special Operations Command United States Special Operations Command (USSOCOM) U.S. Department of Defense (DoD)
Facebook
Tune in as our Air Force musicians along with other military musicians are awarded the National Medal of Arts.
Facebook
Like Us
Twitter
1,262,781
Follow Us