Keywords in material innovation keep popping up. Sustainability, of course. Lightweight, translucent and smart materials, too. Materials that conserve or produce energy are becoming more common, as are biobased and biodegradable materials.

These last two themes combine in a powerful idea: biodegradable energy cells. Researchers at Illinois University have developed electronics that dissolve in water or in organic tissue within a few days. This means that short-lived electronic implants could soon be developed for use within human bodies.

The batteries use trace amounts of metals, such as magnesium, iron, molybdenum and tungsten. The developers state that the amounts are small enough that they aren’t harmful to human beings. The magnesium form the anodes and the other metals the cathodes of the batteries. They are suspended in a phosphate buffer and saline solution. The crucial part is the packaging: a polyanhydride, which is a biodegradable polymer that consists mostly of carbon and oxygen.

This is great news for the biomedical industry, as there’s a huge demand for small, low-power electronics that are less invasive than current technology, including pacemakers. All of the metals used are bio-compatible. That means that they form ions inside the body that do no harm.

Assuming further innovations could reduce the amount of relatively heavy metals in these batteries, we could even be seeing the bio-power in outdoor applications. One idea put forward by the researched is to track the plastic sea in the pacific ocean. Small wireless elements could float about, measuring the dispersion of waste, until they dissolve in the ocean’s water.

More information and images are here.