Communication Networks for Cellular Nanorobots
Biological cellular-based nanorobotics may be able to piggyback on what evolution has already accomplished. Instead of miniature machines, these would be genetically engineered “intelligent” artificial cells. They may have a greater range of abilities than their evolved counterpart as they would be designed to fulfill specific niches. There has been recent work on genetic logic gates for robust digital-like synthetic biology. This is dissimilar to how an electronic circuit runs. The operation happens by way of signal transduction, instead of the flow of current. It might be easier to function in a messy environment. Another mechanism for computation is microbial nanowires derived from the bacterium Geobacter sulfurreducens. The filaments conduct electricity. They are 3 to 5 nanometers in size and can be several micrometers in length. Perhaps these could be utilized in a cell to provide information-processing capabilities. A protein memristor might even enable a nano-neural network for a tiny brain.
Molecular nano-communication is being investigated to facilitate nanodevices to crosstalk. There are numerous routes to allow nanotechnology to do this. One option is calcium signaling. Certain cells absorb or release calcium ions in response to a stimuli. The atoms move from one individual organism to another. Charged particles may alter the membrane potential. The change in voltage might be employed to relay an impulse on a protein wire or the calcium could alter intracellular pathways. A swarm of synthetic cells might have a better capability to process what is happening in their surrounding environment. This may help coordinate their movement. Quorum Sensing is a way that a bacterium regulates gene expression on a population wide scale. Complex molecules can adjust the operations of a second organism. The compounds proceed through a medium, eventually binding to a receptor. They would send bits to be processed by internal structures. Maybe even a small virus-like molecule could transfer from one cell to a second one in order to transmit data. The viral DNA needs to insert itself only in a particular target area. This is a relatively large packet of information. A more speculative approach to guide motion is by using light. Optogenetic proteins are sensitive to different kinds of electromagnetic radiation. When a photon hits the molecule it causes an ion channel to open and thus recalibrates the inner cellular environment. Perhaps several of these avenues can be combined together in a single unit.
Encoding a message could be done by altering various parameters of the cells. DNA can store information. There would have to be a technique to translate the collected info into the reading or writing of a DNA sequence. A future cell may gather data and then discharge it as needed. Over the coming decades, biotechnology should produce a myriad number of unique lifeforms. The new capabilities may even impress many nano-skeptics.
An additional overview is at this site: “Engineering Cellular Control“.
