This month has been loaded with new stories: the International E-waste Day, solar cells printed on paper, wearable sensors printed on skin, and others that are powered by movement! Catch up on the monthly news from the field of printed electronics in our October digest below.
Solar Cells printed on our favourite material… paper!
Paper is an environmentally friendly alternative to plastic and other non-biodegradable materials used to manufacture electronic devices. That’s why at INNPAPER we are developing an electronic platform using paper as a base material, to demonstrate the wide potential of this technology. We aren’t the only ones who pursue this goal! Researchers from India have printed organic solar cells on paper! These devices convert the energy of light into electricity and they are a promising alternative to power flexible electronic devices, even in indoor lighting environments. According to the scientists, the results are among the highest reported efficiency for organic solar cells built on paper substrates.
New tattoos! Sensors printed directly on human skin
Wearable sensors are taking the world by storm! One of the main challenges for scientists is to make this technology comfortable for users. That’s why sensors have been integrated into accessories such as garments, hats, wrist bands, socks, shoes, glasses and other devices including wristwatches, headphones and smartphones. Now, researchers have taken the evolution one step further by printing sensors directly onto the skin! This process has been hindered by the extremely hight temperatures needed for the bonding of the metal components in the sensor. However, researchers found that using a layer made of polyvinyl alcohol – the main ingredient in peelable face mask – and calcium carbonate from eggshells, the process can be carried out at room temperature. “It could be recycled, since removal doesn’t damage the device. And, importantly, removal doesn’t damage the skin either. The device can be useful without being an extra burden to the person using it, or to the environment,” explained one of the scientists.
Wearable sensors powered by movement
Heart rate and body temperature, blood sugar levels, metabolic products and a wide range of disease biomarkers can be monitored in real time thanks to wearable sensors. However, these electronic devices need a source of power. Batteries are an option, but are not ideal because they could be bulky, heavy and run out of charge. That’s why researchers from Caltech have been developing new ways for charging these sensors using the human body! And they had a great idea: using the kinetic energy that is produced by a person as they move around. Using different materials, the scientists created a nanogenerator that produces electricity thanks to friction. Then, this electricity is stored in a capacitor until there is enough charge to take a reading from the sensor and wirelessly send the data to a cell phone through Bluetooth. Overcoming this challenge may pave the way for future applications!
Real talk on International E-waste day
A record 53.6 million metric tonnes (Mt) of electronic waste was generated worldwide according to the UN’s Global E-waste Monitor 2020. The information is alarming: it is estimated that by 2030 this number will reach 74 Mt and only 17.4 % of 2019’s e-waste was collected and recycled. This results in the huge loss of valuable and critical raw materials from the supply chain and causes serious health, environmental and societal issues through illegal shipments of waste to developing countries. That’s why The Third International E-Waste Day took place on 14th October. This time, focused on the theme of education and with a clear aim: encouraging consumers to recycle their e-waste.
Scientists are also doing their bit, as more and more studies seek to improve the electronic waste recycling process. This one using bacteria is a good example!