Looking to the future: In their search for a sustainable alternative to polymer-based circuit boards, researchers found a fungal structure that could solve the problem with an all-natural, biodegradable material. Are bio-organic electronics on the horizon?
Devising the right recipe for durable electronics is one of the most pressing issues facing the industry today. A potential solution could come from mimicking life and nature itself or the part of it that usually lives underground as a support network for fungi and mushrooms. This network, known as the mycelium, has demonstrated interesting properties in sustainable technology and electronics.
According to research conducted by Austrian scientists aptly named MycelioTronics, the fungus Ganoderma lucidum covers its mycelium with a skin-like substance to protect it from bacteria and other fungi. Once the skin is removed and dried, researchers have found that it develops many of the properties found in printed circuit boards (PCBs) used in all technological devices on the market.
The skin of Ganoderma lucidum mycelium is thin and flexible but can retain its structural integrity, withstanding over 2000 cycles of flexing while showing only moderate strength when bent multiple times. The material is a good insulator and can withstand temperatures in excess of 200 degrees Celsius, even higher than those supported by the toughest PCBs (150 degrees Celsius).
To test the skin’s viability as a PCB-like material, the researchers coated the dried skin with a layer of copper and chromium (with an additional layer of gold for some samples to improve conductivity). After using traditional laser techniques to imprint conductive lines on the coated skin, scientists found that the material behaves like a real PCB while being biodegradable under specific conditions. The coated skin can last for hundreds of years when stored in a dry environment, such as inside a smartphone or PC, but quickly breaks down when exposed to moisture and to UV rays.
As explained by Dr. Martin Kaltenbrunner, one of the researchers who designed the new material, PCB is one of the most difficult electronic components to recycle or reuse. Whether it’s a computer, smartphone or whatever, the crude oil-based polymers used to create the panels are usually incinerated or stored in a landfill. A biodegradable alternative would be an “important first step” in developing environmentally friendly electronics.
“Electronic devices are irrevocably embedded in our lives,” the researchers explained. “Yet their limited lifespan and often unplanned disposal demand sustainable designs to achieve a green electronic future. Research should focus on the substitution of non-degradable and difficult-to-recycle materials to allow easy biodegradation or recycling of electronic devices.