Scientists from Chalmers University of Technology have developed a new thread made of conductive cellulose that could be working into textiles, which produce electricity for a range of applications.
Sozan Darabi, a doctoral student at Chalmers University of Technology's, is the lead author of this research paper who was recently published through ASC Applied Materials & Interfaces, while her partners had previously succeeded in producing electrically conductive silk fibers. Now the team has shifted their focus on developing cellulose due to its tremendous potential.
An ink-based biocompatible polymer "polyelectrolyte complex poly (3, 4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS)" is used to coat the electrically conductive yarn in a "layer-on-layer" coating method. The researchers' e-textile thread has a record-high conductivity of 36 S/cm for cellulose thread in relation to volume that could be improved to 181 S/cm by adding silver nanowires. The PEDOT: PSS thread can tolerate at least five machine washes before losing its conductivity. This “layer-on-layer" coating method transforms the cellulose thread into a conductive one, with the team claiming that it has a record high conductivity for a cellulose thread that can be increased even further with the inclusion of silver nanowires. The resultant thread could be sewed into cloth using a home sewing machine to create a thermoelectric fiber which produces electricity when heated on one hand. The team uses body heat as an instance, stating that a temperature difference of 37 °C (98 °F) will cause the textile to generate about 0.2 microwatts of electricity (assuming the person is standing in the freezing cold).
“This cellulose thread could lead to non-toxic, reusable, and natural garments with built-in electronic, smart functions,” says Sozan Darabi. These types of garments may be helpful in a number of contexts, and the researchers claim they have more scope in medical care, where they could be used to monitor various health indicators. The use of cellulose could increase the produced product's reusability and recycling properties, however the threads can only survive five system washes before destroying their electrical conductivity.