The present invention relates to a method for preparing three-dimensional actin structures having a well-defined shape and displaying improved mechanical rigidity. This method comprises the steps of (a) providing a polymerization solution comprising actin monomers, a branching agent and a capping agent, (b) providing at least one surface having thereon a pattern which is coated with a nucleating agent, and (c) contacting the at least one surface of step (b) with the polymerization solution of step (a) so as to induce the polymerization of actin and obtain the said desired three-dimensional actin structure. Applications of the present invention in various technological fields such as microelectronics are also provide
