Expansions at small Reynolds numbers for the locomotion of a spherical squirmer

The locomotion of a spherical squirmer — a model organism that achieves self-propulsion via steady tangential movement of its surface — is quantified at small Reynolds number R. Matched asymptotic expansions are employed to calculate the swimming velocity of the squirmer through O(R2). Approximations to the velocity and vorticity fields around the squirmer that are uniformly valid to O(R) are also constructed.