Biodegradable Electronics: What Fungi, Algae, and Crab Shells Can Do

According to a UN report, a record 62 million metric tons of e-waste were generated in 2022, 82% more than in 2010. Only 22.3% of it was documented as having been properly collected and recycled. Scientists are therefore trying to change the materials themselves: using mycelium-based substrates instead of epoxy resin, and gels made from the waste of marine animal shells instead of corrosive electrolytes. Most of these solutions are still in the laboratory stage, and none of them replaces the chip, metals, or lithium battery in today’s phones.

Why E-Waste Recycling Can’t Keep Up

E-waste is accumulating faster than the world can process it. According to the report, the annual volume is growing by 2.6 million metric tons and is expected to reach 82 million metric tons by 2030. Meanwhile, the proportion of properly recycled waste is estimated to drop from 22.3% to approximately 20%. In 2022, waste contained 31 million metric tons of metals and 17 million metric tons of plastics. If managed improperly, approximately 58,000 kg of mercury and 45 million kg of plastics containing brominated flame retardants are released annually.

Printed circuit boards are particularly difficult to recycle. They typically consist of glass fibers bonded with epoxy resin—a fossil-based material that does not decompose and is difficult to separate from the components. This is precisely why scientists are focusing on finding alternatives.

Biodegradable electronics made from mushrooms: printed circuit boards made from mycelium

What scientists have already created

Mycelium is the network of fibers from which fungi grow. A team from Austria’s Johannes Kepler University has developed an approach called MycelioTronics, in which they cultivate thin “skins” from the filaments that can be used as a substrate for sensors and batteries. As a demonstration, they assembled a device with a battery, a Bluetooth module, and a sensor on a mycelium board. After use, the board decomposed in a compost bin.

More recent research from the University of Freiberg in Germany uses the mycelium of the fungus Aspergillus niger, which is produced as a byproduct of industrial citric acid production. The researchers pour the biomass into molds and air-dry it, producing boards approximately 5 mm thick with a density of 1.23 g/cm³, comparable to standard printed circuit boards. The material is biodegradable according to ISO 20200 and disintegrates when placed in water. This allows functional components to be extracted from it, which the researchers demonstrated by re-soldering them onto a standard circuit board.

Why It’s Not in Phones Yet

The authors are referring to boards for simple circuits, not the complex multilayer boards found in modern smartphones. This raises a fundamental contradiction: electronics must withstand moisture and heat, yet they are supposed to decompose at the end of their lifespan. Heat treatment at 120 °C improves strength and water resistance, but at the same time slows down biological decomposition. The European Research Council is funding the MycoSub project, which aims to produce flexible boards made of mycelium that are compatible with industrial processes. However, this is the project’s goal, not a finished product.

Batteries Made from Crab Shells: What We Already Know About Chitosan

Chitin is extracted from the shells of crabs, shrimp, and lobsters, and from this, chitosan—a biodegradable substance—is produced. Scientists from the University of Maryland and the University of Houston used it to create a gel electrolyte for a zinc battery. According to the authors, about two-thirds of the battery is biodegradable, and in tests, the electrolyte completely decomposed in approximately five months. What remains is zinc, which can be recycled. After 1,000 charging cycles, the battery maintained 99.7% energy efficiency.

It is important to note the intended purpose of this research. The prototype is designed to store energy from wind and solar sources, not to power a smartphone. The authors consider it possible to extend this technology to other types of batteries, but a finished version for phones does not yet exist. Furthermore, the results date back to 2022.

Seaweed and Other Natural Polymers

Alginate, a water-soluble polymer, is extracted from brown algae. An Italian team used it to create a flexible substrate for organic light-emitting diodes (OLEDs) and demonstrated that the device can be disassembled, allowing nearly all of its valuable materials to be recovered. The sources I found show substrates and adhesives like this. There are no finished electronic enclosures made from seaweed among them.

Can you bury an old phone in the garden?

The image of a phone decomposing in the ground into fertilizer is appealing, but it doesn’t align with research. In prototypes, only the substrate or part of the battery is biodegradable. Chips, metal wires, and solder remain. Moreover, biodegradable material must also withstand years of normal use.

A more meaningful goal is the opposite: to design electronics so that they can be easily disassembled and valuable components recovered. A circuit board that disintegrates in water makes this possible. The value is high: according to a UN report, undocumented waste from 2022 contained raw materials worth about $62 billion. Just as important as the materials is collection. If countries were to increase collection and recycling to 60% by 2030, the benefits would exceed the costs by more than $38 billion, according to the report.

When Will Biomaterials Be Integrated into Mainstream Facilities?

Sources do not specify timelines for commercial deployment. However, it can be assumed that simple, short-term devices—such as disposable sensors, where performance requirements are low and biodegradability after use is an advantage—will be the first to be adopted. In complex devices, such as smartphones, the challenge of balancing durability, manufacturing processes, and cost remains unresolved.

Conclusion

Mycelium boards, chitosan electrolytes, and alginate substrates demonstrate that some electronic components can be made from renewable and biodegradable materials. So far, these are prototypes for simple devices. The real benefit today seems to lie more in easier recycling than in spontaneous decomposition. Until electronics are designed to be disassembled and collection becomes significantly more efficient, the new materials alone will not solve the problem of electronic waste.