Some people believe that in the future, man will be melded with machine to overcome our weaknesses. While there are definitely some efforts being made on advanced implants and prosthetics, some are looking to combine electronics and organisms in a different way. At MIT researchers have modified bacteria cells to act as calculators with the ability to perform the five geometric operations as well as logarithms.
This is not the first time that cells have been modified to perform calculations, but unlike many of those previous experiments, the MIT bacteria are analog instead of digital, which comes with many advantages. Analog signals exist on a continuum, so one signal can carry quite a bit of information, compared to a single digital signal that is either 0 or 1. This allows for simpler circuits, such as the square root circuit which only has two parts, compared to the digital equivalent that has over 100. Another important advantage for analog circuitry is that cells already respond to analog signals, so the circuits could take advantage of existing mechanisms.
The researchers created their calculator from just three basic parts and are now working to develop more parts, to potentially create a library of parts to be used in cellular circuits. Eventually this could lead to more advanced molecular sensors, gene expression, as well as cellular computation and actuation.