All-Natural Smart Mycelium Surface with Tunable Wettability

A naturally occurring smart mycelium surface with tunable wettability is demonstrated. The commercially produced mycelium foam shows a natural hydrophobic and nonabsorbent surface with water contact angles well above 135°. The surface maintains its hydrophobicity and nonabsorbance after being compressed into a thin film under pressure and mild temperatures. We report that this surface carries tunable wettability. We have shown that a facile water treatment followed by room-temperature drying initially renders the surface highly hydrophilic and absorbent. Subsequent conditioning at 50 °C at any relative humidity turns the surface back to hydrophobic and partially restores nonabsorbance with a switchable character. We show that this change in surface wettability can be attributed to the increased water contact area and the surface hydroxyl groups of the fungal hyphae and the tunable property can be attributed to the presence of the surface amphiphilic protein, hydrophobin.