Grow with the flow - observing the formation of rheotactically patterned bacterial cellulose networks

The use of matrix-forming organisms is a promising way to obtain hierarchically structured materials. In this work, we investigate the rheotactic bio-mediated alignment and network formation of bacterial cellulose streamers, resulting in hierarchically patterned textiles. For this purpose, we devised a panoramic-view observation setup for a microfluidic cell. We observed a split growth, with first, a flow-aligned streamer formation and second, a streamer connection phase. The growth phase parameters showed dependence on flow rate. After aligned growth, a mineralisation step was conducted to the grown textiles with calcium carbonate and -sulfate to obtain nature-inspired organic/inorganic composite materials. Hereby, an anisotropic deposition of the gypsum phase due to the prealigned bacterial cellulose substrate was observed.