The Kuhn length is a theoretical treatment of a real polymer chain divided into <math>N</math> Kuhn segments with Kuhn length <math>b</math>, so that each Kuhn segments can be thought of as if they are freely joined with each other. The contour length <math>L=Nb</math>. The construction is useful in that it allows complicated polymers to be simply modeled as either a random walk or a self avoiding walk. For semiflexible chain, Kuhn length equals two times the persistence length.
