Lately, a lot of work has been done by a number of research groups to create insect-like electromechanical drones. We argue that such drones would suffer from a very limited range and availability of energy, and that for a very long time their efficiency and capability to operate autonomously would be incomparably lower than those of biological systems. The biological systems also have an ability to replenish their energy almost infinitely by consuming natural food, thus they are not dependent upon solar energy.
Therefore, it appears that the most promising drone systems would be the natural insects interfacing the tiny implanted microelectronic chips. The control of the insect movements by electronic means has been demonstrated by supplying current of certain frequencies to the chemoreceptors of the insects. The important part is development of transduction of the biochemical energy of the insect into the electric energy sufficient to drive the embedded microchip.
An insect converts the consumed food primarily into ATP in mitochondria via glycolysis – Citric acid cycle-electron transport chain pathway. The energy of glucose is converted by the proton pumps into the proton gradient between the mitochondrial matrix and the intermembrane space, as shown on the attached picture. The proton gradient is used to generate ATP from ADP by ATPases in the inner mitochondrial membrane.
Thus, through a series of the very high-efficiency trasformations, the energy of food is converted into the constantly maintained potential difference across the inner membrane of mitochondria. That electric energy could be transducted into ATP, or it could be used to power the embedded microchip.
To use that energy, we create a giant compound mitochondria by connection of a multitude of mitochondria via the membrane bridges. Then we attach electrodes to the matrix and intermembrane space of the compound mitochondria, and place it into the intracellular space, where it has an access to the nutrients.
Mitochondrial proton gradient is used to generate ATP. Some of that ATP is needed for glycolysis, the initial stage of liberation of the energy stored in glucose. Mitochondria exports the excess of ATP via the ATP/ADP transporters in its outside membrane. However, we do not need much of ATP in the extracellular space, for it might cause apoptosis of the neighboring cells. Therefore, we knock down most of ATPases and ATP/ADP transporters of the compound mitochondria, to produce ATP in the amounts just enough for glycolysis. The chief function of the compound mitochondria is not ATP generation, but maintenance of the highest possible proton gradient.
The membrane of the compound mitochondria is modified to protect it from the immune system of the insects.
A direct transduction of the biochemical energy stored in the natural food into the electric energy is a pioneering achievement that would affect not only the field of insect drones, but also the general ways of energy generation, where entropy of energy transduction is greatly decreased and the resulting free energy is greatly increased.