～Nano Bio Battery～
Recently some researches about bio-battery, which can generate electricity from energy produced by biological activities, have been published.
We are going to give you the idea of the mechanism which can produce (electric) energy inside the body with liposome, which have biocompability.
First, two water drops are put into oil and joined with each other. The complex of the two water spheres are covered with lipid monolayer membrane.
Next, the complex is frozen to stabilize, and then covered with one more lipid monolayer membrane on the drops. Stabilized complexes of liposome are obtained.
Potassium ions (cation) and anionic fluorescent beads are inserted into one of the two spheres ,while potassium indicator into the other.
Both the two kinds of ion (cation,anion) tried to move the other side through the hole made in advance, according to the concentration gradient.
However, by the difference of the size of the ions against the holes, the smaller ones (=cation:K+) can only pass through the hole selectively.
This allows a potential difference to be generated.
In the future, this device can be a bio-battery which can supply electricity for implantable electronic equipment safely and stably.
So, that is expected to be put to practical use in medical field.