Smart sensor-based textiles: "Lab coats or textile-based wound dressings are possible areas of application"

Interview with Dr. Gerhard Mohr, project manager at the JOANNEUM Research Forschungsgesellschaft mbH

Researchers at the JOANNEUM Research Institute are developing textiles that change their color when they are exposed to toxic or hazardous substances. Whether it’s at the laboratory, hospital or at home – these smart sensor-based textiles could have a wide variety of applications. spoke with Dr. Gerhard Mohr about special dyes and sensitive baby skin.


Photo: Dr. Gerhard Mohr

Dr. Gerhard Mohr; © Bernhard Bergmann

Dr. Mohr, you developed smart sensor-based textiles that react with toxic gases or fluids. How does that work?

Gerhard Mohr
: To be more precise, we develop dyes that give the textiles special properties. They are coated with special dyes and the textile then changes its color and warns the user when it comes in contact with substances such as carbon dioxide for instance.

What application areas are intended for these textiles?

: Lab coats or work gloves are possible applications. They are being coated with dyes that respond to substances that could burn your hands or if carbon monoxide is in the air – a poisonous gas that you can neither smell nor taste.

Other application areas include textile-based wound dressings in clinical diagnostics with which you can measure pH levels in wounds. You could color wound dressings with dye that for instance changes its color from green to red in case of increasing pH. This is therefore an immediate signaling effect: green means everything looks good; red means you need to act accordingly.

When you slightly expand the term textiles, you get into the area of unspun materials like cotton swabs for instance. Nurses or hospital staff could use such dyed cotton swabs to clean patient wounds.
Photo: Undiscolored and discolored pavement

Wound dressings such as plasters discolor when the patient has to high pH level in the skin; © JOANNEUM Research Forschungsgesellschaft

How solidly are the dyes adhered to the textiles?

: The textiles are immersed into the dye solution and the dye exhibits a chemically active response – it therefore adheres solidly to the fiber. So solidly in fact to where it cannot be rinsed out, even if the textile is decocted at 95 degrees Celsius.

It is very important that the chemical dyes adhere this solidly to the fiber, since they must not come in contact with the skin or wounds.

Is there a different dye for each substance?

: Depending on which substance is meant to be determined – whether it’s pH levels or ammonia in a diaper – you need a different dye. The dyes therefore require very special preparations.

Which substances have they been tested for already?

: At the moment, we conduct pH measurements for medical textiles. Generally, ammonia and amines can also be detected with our dyes. Carbon dioxide and carbon monoxide are possible in the area of gases. We also synthesize other dyes that have not been comprehensively characterized yet. They are designed to react with heavy metals or nitric oxides.

Photo: Indicator swab

The dyes may also be applied to unspun materials; © JOANNEUM Research Forschungsgesellschaft

To what extent are the dyes being used already?

: Currently we are producing the dyes we developed on a small scale and test them on the different applications. However, it is definitely conceivable to produce the dyes on a larger scale. The dyeing process would need to be performed by a textile refining company for instance. We would then adapt the materials we develop to the production process of the respective company.

Besides lab coats or wound dressings, what application areas are also conceivable for the dyes?

: We are also working on a washcloth for babies. Baby skin is very sensitive. The pH level in many laundry detergents is too high for babies, which leads to skin irritation. This is why we are developing a washcloth with an indicator dye that warns against high pH levels. Aside from newborns, this type of washcloth could also be interesting for people suffering from neurodermatitis, who have extremely sensitive and irritable skin.

Photo: Michalina Chrzanowska; Copyright: B. Frommann

© B. Frommann

The interview was conducted by Michalina Chrzanowska and translated by Elena O'Meara.