Tag Archives: tannic acid

Red wine for making wearable electronics?

Courtesy: University of Manchester [1920_stock-photo-red-wine-pouring-58843885-927462.jpg]

A July 12, 2019 news item on Nanowerk may change how you view that glass of red wine,

A team of scientists are seeking to kick-start a wearable technology revolution by creating flexible fibres and adding acids from red wine.

Extracting tannic acid from red wine, coffee or black tea, led a team of scientists from The University of Manchester to develop much more durable and flexible wearable devices. The addition of tannins improved mechanical properties of materials such as cotton to develop wearable sensors for rehabilitation monitoring, drastically increasing the devices lifespan.

A July 11, 2019 University of Manchester press release, which originated the news item, describes how this new approach could affect the scientists’ previous work,

The team have developed wearable devices such as capacitive breath sensors and artificial hands for extreme conditions by improving the durability of flexible sensors. Previously, wearable technology has been subject to fail after repeated bending and folding which can interrupt the conductivity of such devices due to tiny micro cracks. Improving this could open the door to more long-lasting integrated technology.

Dr Xuqing Liu who led the research team said: “We are using this method to develop new flexible, breathable, wearable devices. The main research objective of our group is to develop comfortable wearable devices for flexible human-machine interface.

“Traditional conductive material suffers from weak bonding to the fibers which can result in low conductivity. When red wine, or coffee, or black tea, is spilled on a dress, it’s difficult to get rid of these stains. The main reason is that they all contain tannic acid, which can firmly adsorb the material on the surface of the fiber. This good adhesion is exactly what we need for durable wearable, conductive devices.”

The new research published in the journal Small demonstrated that without this layer of tannic acid, the conductivity is several hundred times, or even thousands of times, less than traditional conductive material samples as the conductive coating becomes easily detached from the textile surface through repeated bending and flexing.

Here’s a link to and a citation for the paper,

A Nature‐Inspired, Flexible Substrate Strategy for Future Wearable Electronics by Chuang Zhu, Evelyn Chalmers, Liming Chen, Yuqi Wang, Ben Bin Xu, Yi Li, Xuqing Liu. Small Online Version of Record before inclusion in an issue 1902440 DOI: https://doi.org/10.1002/smll.201902440 First published: 19 June 2019

This paper is behind a paywall.

Never bleed again? New nanoscale bio coating stops bleeding in seconds

It’s not quite instantaneous but the new nanoscale biological coating devised by MIT (Massachusetts Institute of Technology) engineers at their Institute of Soldier Nanotechnologies cuts bleeding time to less than 1/2 of what it was (from 150 seconds to 60 seconds) in animal tests. The Jan. 10, 2012 news item on Nanowerk provides more detail,

MIT engineers have developed a nanoscale biological coating that can halt bleeding nearly instantaneously, an advance that could dramatically improve survival rates for soldiers injured in battle.

The researchers, led by Paula Hammond and funded by MIT’s Institute of Soldier Nanotechnologies and a Denmark-based company, Ferrosan Medical Devices A/S, created a spray coating that includes thrombin, a clotting agent found in blood. Sponges coated with this material can be stored stably and easily carried by soldiers or medical personnel.

The Jan. 10, 2012 news release by Anne Trafton for MIT notes,

Uncontrolled bleeding is the leading cause of trauma death on the battlefield. Traditional methods to halt bleeding, such as tourniquets, are not suitable for the neck and many other parts of the body. In recent years, researchers have tried alternative approaches, all of which have some disadvantages. Fibrin dressings and glues have a short shelf life and can cause an adverse immune response, and zeolite powders are difficult to apply under windy conditions and can cause severe burns. Another option is bandages made of chitosan, a derivative of the primary structural material of shellfish exoskeletons. Those bandages have had some success but can be difficult to mold to fit complex wounds.

Many civilian hospitals use a highly absorbent gelatin sponge produced by Ferrosan to stop bleeding. However, those sponges need to be soaked in liquid thrombin just before application to the wound, making them impractical for battlefield use. Hammond’s team came up with the idea to coat the sponges with a blood-clotting agent in advance, so they would be ready when needed, for either military or civilian use.

To do that, the researchers developed a nanoscale biological coating that consists of two alternating layers sprayed onto a material, such as the sponges used in this study. The researchers discovered that layers of thrombin, a natural clotting protein, and tannic acid, a small molecule found naturally in tea, yield a film containing large amounts of functional thrombin. Both materials are already approved by the U.S. Food and Drug Administration, which could help with the approval process for a commercialized version of the sponges, Shukla [Anita Shukla PhD ’11] says.

A key advantage of the spray method is that it allows a large amount of thrombin to be packed into the sponges, coating even the interior fibers, says David King, a trauma surgeon and instructor in surgery at Massachusetts General Hospital who was not involved in this research.

“All of the existing hemostatic materials suffer from the same limitation, which is being able to deliver a dense enough package of hemostatic material to the bleeding site. That’s why this new material is exciting,” says King, also an Army reservist who has served in Afghanistan as chief of trauma surgery.

Very exciting stuff but no word as to when it might reach the marketplace. A patent application has been filed but it doesn’t seem that any human clinical trials have been held yet. As best I can determine, all of the testing done (at Ferrosan) so far has been on animals.

I did check out the Ferrosan website and found this on their About page,

Ferrosan is an international consumer health company with strong market positions and a solid financial performance.

We strive for optimal development by selectively aiming for position as a leader through organic as well as M&A-driven growth.

In order to accomplish our objectives each employee must deliver upon Ferrosan’s values:

  • Get things done
  • Exceed expectations
  • Appreciate individual differences
  • Enjoy and have fun

The foundation of our future success is based on each employee’s ability to make a difference.

Ferrosan is a well established pharmaceutical company with a great heritage. In 2010, we celebrated the company’s 90th anniversary.