Advanced Manufacturing of Mycological Bio-Based Composites

Abstract

The development of bio-based materials continues to be driven by the need to reduce the environmental impact on our planet. The development of materials made from fungi, known as mycological composites, is becoming an emergent field in the range of bio-based materials being developed. Motivated by commercial and consumer demand for less ecologically damaging options, mycological composites continue to grow as a sustainable materials option, offering reduced environmental impact due to being made from waste by-products from industrial processes such as sawdust. Naturally occurring fungi species can digest a range of carbon-containing wastes, and can convert them into bio-based composites materials formed of the fungi and the original feedstock. Current applications require mycological composites to be shaped using traditional subtractive mechanical methods, which can cause chipping and surface damage due to the frangible nature of mycological materials. Nontraditional manufacturing techniques were considered, including water jet machining, ultrasonic machining, electrochemical and electrical discharge machining, and laser cutting, to help inform developers and researchers of suitable alternative manufacturing methods. Laser cutting was determined to be the most suitable method to test, offering precision cutting without mechanical abrasion, and optional pyrography. Testing showed bulk cutting can be achieved for thin slices of material, and small feature cutting testing showed laser cutting is suitable for creating small features. The average laser cutting kerf was found to be comparable to band and table saw kerfs, with had advantages of a variable outline cutting paths and producing no cutting waste. Laser pyrography testing showed laser cutting can also be used to burn vector images into mycological materials, with potential to combine with cutting into a single process step. Overall laser cutting was found to provide a suitable non-mechanical cutting process that could create features that could not be cut using traditional subtractive or mechanical processes.