Biodegradable

Although it's always best to reuse and recycle, many small, simple, low-power electronic devices tend to be single-use. A new paper battery could make them more eco-friendly, as it's activated by water, and it biodegrades once discarded.

Nobody wants to suffer physical pain if they don't have to, yet they also don't want to risk developing an addiction to pain-killing opioids. That's where a new drug-free implant comes in, as it reduces pain by cooling nerves.

We've seen a number of odd merino wool products over the years, but that didn't prepare us for wool bandages. New Zealand's WoolAid says that its natural bandages are better for healing and better for the environment.

Last year, scientists at Northwestern University announced a transient pacemaker that dissolves when no longer needed. They've now improved the device, and incorporated it into a linked suite of wearable sensors.

Discarded shoes are a particularly bulky form of waste, with their molded rubber soles joined to often synthetic uppers. Blueview shoes reportedly offer a greener alternative, however, as they're claimed to completely biodegrade once thrown away.

While all non-recyclable plastics aren't very eco-friendly, expanded polystyrene foam is particularly problematic, as it's bulky and often used in disposable packaging. It could be replaced by a new biodegradable material, however, made from sawdust.

If you're designing a plastic for applications such as food packaging, you want it to stay clean but you don't want it to stick around for centuries once discarded. A new lotus-leaf-inspired material may fit that bill.

It's ironic that even though many people are starving, a great deal of food gets discarded because it spoils before it can be eaten. A new natural-source packaging material could help, by making foods last longer – plus it's biodegradable.

As 3D-printed electrical circuits become more widely produced, the problem of electronic waste could correspondingly get worse. That's why Swiss scientists have developed a new natural-source "e-ink" that biodegrades once discarded.

Although there are now biodegradable single-use electronic devices such as environmental sensors, the batteries in those devices can still pose an ecological problem. That's why scientists have now created a fully biodegradable paper-based battery.

Expanded polystyrene (EPS) foam is a problematic material, in that it's cheap and lightweight but also non-biodegradable and difficult to recycle. German scientists have developed a possible alternative, though – foam made out of popcorn.

Scientists at Finland's VTT Technical Research Centre have been developing an alternative leather made from fungi, and have now demonstrated a way to produce continuous sheets of the stuff at commercial scales.