Protein-based materials can be genetically customized for a range of applications.  In addition to displaying biocompatibility, tunable bioactivity and responsiveness, they represent sustainable alternatives to conventional synthetic polymers.  In particular, proteins that self-assemble into higher order structures and can be produced at large scale are of interest for deployment into wearable devices and alternatives for commodity materials like plastics, textiles and electronics.  Curli fibers produced as part of the extracellular matrix of Escherichia coli bacteria represent a promising protein scaffold, due to their unique physicochemical properties, including their ability to self-repair and their resistance to harsh conditions.  Once secreted by bacterial cells, CsgA subunits, the self-assembling repeats of curli fibers, form fibrous structures that can further aggregate, entangle, and gel into macroscopic materials.  Among other functionalities, we have genetically encoded in CsgA the ability to fluoresce, to conduct charges, and to respond to stimuli.  
In this talk, I will present advances that my group has made to engineer textile-protein composite materials containing functional curli fibers.  The engineered curli fibers allow to modulate the mechanical, self-healing and sensing properties of the composites, making them proposing candidates for designing responsive apparel.  I will begin by summarizing scalable and simple bioprocesses that we have developed to express, extracellularly secrete, and deposit genetically engineered curli fibers on textiles or other porous supports.  Then, I will present applications of engineered curli fibers and bacterial biofilms as wearable biosensors and as “living” self-repairing textile glue. These novel bio-derived devices on fabric enable functions that can only be achieved by biological materials, and could be further fine-tuned to respond to the needs of biomedical and fitness industries.