Despite its bad rep, body fat fulfills an essential evolutionary function: accumulating energy reserves for moments of shortage and protecting from potential impacts. Unlike robots, human beings and other animals do not store their energy in a specific compartment but rather distribute it throughout various areas of the body. Otherwise, we would have to carry a sack of fat, which would be very inefficient when it comes to transforming it into energy. And perhaps a little unsightly.
On the other hand, machines must incorporate a specifically dedicated load, which increases the structure’s weight and size, reaching a fifth of its space. However, an innovative technology project could change that substantially.
At the University of Michigan, they have developed a new generation of “biomoprhic” batteries that imitate the animals’ body fat. Based on zinc instead of lithium, this technology is more efficient since it fulfills a double function: as a protective structure or shell and as an energy store.
In the experiments they have carried out, the new structural batteries have generated up to 72 times more energy than a conventional lithium battery. In technical terms, the new batteries work by transmitting hydroxide ions from a zinc electrode through a network of aramid nanofibers, which are used in the manufacture of Kevlar, and a water-based polymer gel. In this case, the gel is in charge of conducting the ions from one electrode to another.
Cheap and eco-friendly… though with some drawbacks
One of the advantages of this innovative technology is that the materials used are cheap, abundant, and, for the most part, non-toxic. In fact, it would be possible to recycle Kevlar protective vests to manufacture these new devices. Also, neither the gel nor the fibers are flammable, which reduces the fire hazard of the lithium-based models. Zinc batteries will begin to degrade after 100 charge cycles, a fifth of the cycles offered by curent lithium batteries.
In any case, if this obstacle is overcome, the high density of the new batteries and their low price make them ideal candidates for robots that require greater autonomy, as is the case with drones or vehicles that work in warehouses. Besides, they could have exciting applications in the field of microscopic and flexible robots, which will require more imaginative energy solutions than the current bulky batteries. Who knows if one day even robots too will have to go on a diet.
If you want to see these machines in action, which in the experiments adopt the form of scorpions and other invertebrates, you can take a look at this video.
Source: University of Michigan