2023 Theses Doctoral

Bacterial Spore-based Humidity Responsive Textiles

Ungar, Yocheved

Humidity responsive materials sense, respond and adapt to the environment in response to changes in humidity. An important potential application of this material technology is the creation of “smart textiles” that facilitate moisture management in clothing. Materials used for clothing must have characteristics such as elasticity, washability and abrasion resistance, but smart textiles that have been demonstrated to date lack these characteristics. It is the need for improved materials that motivated the present study.

Here, we developed spore-cellulose nanofiber composites (CNF) and spore-polyurethane (PU) composites, which are two biologically-based humidity-responsive materials that derive their high energy density humidity responsiveness from spores. We demonstrate the use of these hygromorphing materials for smart textiles by coupling the responsive materials to fabrics to create a textile that vents in humid environments and closes in dry environments. This material can be used in clothing to enable fast evaporation of sweat from the skin and improved comfort.

Because the spore-CNF composite is not elastic stretchy or water resistant and therefore is undesirable for real world clothing applications, we also developed a stretchy spore-PU composite that is simultaneously humidity responsive, stretchy and water and abrasion resistant. In addition, we fabricated spore-PU based hygromorphing fabric bilayer actuators to create venting smart textiles with adaptive permeability properties that are compatible with clothing applications. These smart fabrics have the potential to improve the functionality and utility of garments, especially those intended for athleticwear, workwear and protective garments.