Drawing electronics on skin, wearable nanocellulose patches for monitoring body fluids, solar powered supercapacitors, new solutions to recycle e-waste and 3D-printed wireless sensors made of cellulose. Cath up on the monthly news from the field of printed electronics in our August digest below.

Drawing electronics on skin

Pencils are designed for writing and drawing. Now, there are different studies aiming to use pencils for drawing bioelectronic devices on skin which can be used to monitor health conditions. “The conventional approach for developing an on-skin biomedical electronic device is usually complex and often expensive to produce. In contrast, our approach is low-cost and very simple. We can make a similar device using widely available pencils and paper,” explained scientists from the University of Missouri. What’s more, because paper can decompose in about a week, these types of devices are eco-friendly solutions to the e-waste problem. Read more about these inventions here.

 

Electronic circuit drawn directly onto the skin. © University of Houston

A printed patch for monitoring body fluids in sweat

Skin-adherent sensors can be used for non-invasive detection and monitoring of body fluids present in sweat. These devices are usually printed on plastic surfaces, which unfortunately create a barrier between the skin and the sensors, hindering detection and promoting allergies. Now, a team of researchers from Brazil has created a wearable sensor printed on microbial nanocellulose, a natural polymer that allows sweat to reach the electrode’s active layer and facilitates detection. The sensor is a small adhesive rectangle that can detect a great range of biomarkers, such as sodium, potassium, uric acid and glucose, which circulate in the bloodstream and are also detectable in sweat. Diabetes monitoring, hormone control and pollutant detection are some of its applications, according to the authors.

A new hybrid material to protect metal surfaces from electronic waste

According to the United Nations, people will generate more than 52 million metric tons of e-waste per year by 2021, which is a health hazard and a risk to the environment. That’s why finding solutions to this problem has become a priority. However, recycling can be difficult because e-waste contains many different materials which cannot be easily separated. Previous studies have shown that the use of heat could selectively break and reform chemical bonds in e-waste to form new environmentally friendly materials. Therefore, a research team from Australia applied this method to investigate the properties of copper and silica compounds often found in old printed circuit boards and computer monitors. These substances were combined and they created a durable new hybrid material, potentially useful for protecting metal surfaces against corrosion and wear.

“The material (thick gray line in the center of the image) derived from e-waste remained intact when indented, and increased the hardness of the steel below it,” via IEEE Spectrum © ACS Omega

Solar powered supercapacitors for flexible wearables

A team of engineers from the University of Glasgow have created a flexible supercapacitor using layers of graphene and polyurethane, which can generate power from the sun and store excess energy for later use. This breakthrough technology could bring a new generation of flexible electronic devices to life, including solar-powered prosthetics for amputees, wearable health monitors, even electric vehicles that incorporate the technology. “Our new flexible supercapacitor, which is made from inexpensive materials, takes us some distance towards our ultimate goal of creating entirely self-sufficient flexible, solar-powered devices which can store the power they generate,” explained the leader of the research.

3D-printed, wireless sensors made of our favourite material…cellulose!

At INNPAPER we know that paper is rising as a good alternative to traditional materials for electronics, because it’s cheap, flexible, renewable and recyclable, and we aren’t the only ones. A joint research team from Canada and Zurich has developed a 3D-sensor system printed on cellulose that is disposable, ion-selective and can be interrogated wirelessly. According to the researches, these sensors offer a unique combination of form factor, high sensitivity and flexibility. The goal is to replace plastic from common printed circuits boards with eco-friendly and disposable chemical sensors. Read more about the details here.