A theory for the shape of the red blood cell

A theory of mechanical stability is formulated based on the electrostatic energy density contained within a biological membrane. Stable cell shapes are taken to correspond to a minimum value for the total electrostatic energy. The theory is applied to the red blood cell, and it is shown that the normal biconcave shape indeed corresponds to the shape of minimum electrostatic energy. The results are compared with theories based on bending energy relations.