Page 80 - August-September-2017

80 81

Wound-Healing bandage New aqueous transparent FR coating

with a voice Test combustion of paper with (right) and without Landex Coat
Flame Retardant Clear treatment. © Teijin Limited Dainichi Giken,
a pioneer of aqueous inorganic polymers in Japan, has
co-developed a new aqueous transparent flame-retardant
coating, Landex Coat Flame Retardant Clear, in partnership with
Daimaru Kogyo, a leading Japanese chemical trading company,
and Teijin, a technology-driven company with businesses in
advanced fibres, plastics and films, composites, healthcare and
information technology.

Landex Coat Flame Retardant Clear, the halogen-free aqueous
transparent acrylic flame-retardant coating, is said to significantly
improve the flame retardancy of diverse combustibles, including
timbers, papers, fibres, rubbers and plastics. The transparent
coating is simply applied to the surface to maintain the material’s
original texture.

Energy harvesting

yarns generate

Researchers from Empa teamed up with ETH chronic wounds could be monitored at home. This
Zurich, Centre Suisse d’Electronique et de would also mean a gentler treatment for patients, electricity
Microtechnique (CSEM) and University Hospital less work for the nursing staff and, therefore, lower
Zurich to develop a high-tech system that is costs: globally, around US$ 17 billion were spent
supposed to supply the nursing staff with relevant on treating wounds last year, according to Empa. An international research team led by scientists at simple as a mixture of ordinary table salt and water.
data about the condition of a wound. The University of Texas at Dallas and Hanyang “Fundamentally, these yarns are supercapacitors,”
The pH level is particularly useful for chronic University in South Korea has developed high-tech said Dr Na Li, a research scientist at the NanoTech
When wounds heal, the body produces specific wounds. If the wound heals normally, the pH rises yarns that generate electricity when they are Institute and co-lead author of the study. “In a normal
substances in a complex sequence of biochemical to 8 before falling to 5 or 6. If a wound fails to close stretched or twisted. capacitor, you use energy — like from a battery — to
processes, which leads to a significant variation in and becomes chronic, however, the pH level add charges to the capacitor. But in our case, when
a number of metabolic parameters. All these fluctuates between 7 and 8. The yarns are constructed from carbon nanotubes, you insert the carbon nanotube yarn into an electrolyte
variations can be detected with specialised sensors. which are hollow cylinders of carbon 10,000 times bath, the yarns are charged by the electrolyte itself. No
With this in mind, Empa teamed up with project The idea behind the sensors is that if certain smaller in diameter than a human hair. The external battery, or voltage, is needed.”
partner CSEM to develop a portable, cheap and substances appear in the wound fluid, researchers first twist-spun the nanotubes into
easy-to-use device for measuring fluorescence that is “customised” fluorescent sensor molecules high-strength, lightweight yarns. To make the yarns When a harvester yarn is twisted or stretched, the
capable of monitoring several parameters at once. respond with a physical signal. They start glowing highly elastic, they introduced so much twist that volume of the carbon nanotube yarn decreases,
and some even change colour in the visible or the yarns coiled like an over-twisted rubber band. bringing the electric charges on the yarn closer
A novel bandage alerts the nursing staff as soon as ultra-violet (UV) range. Thanks to a colour scale, together and increasing their energy, Haines said.
a wound starts healing badly. Sensors incorporated weaker and stronger changes in colour can be In order to generate electricity, the yarns must be This increases the voltage associated with the
into the base material glow with a different intensity detected and the quantity of the emitted substance either submerged in or coated with an ionically charge stored in the yarn, enabling the harvesting of
if the wound’s pH level changes. This way even be deduced. conducting material, or electrolyte, which can be as electricity.

August/September 2017 August/September 2017