We present a novel method of simulating incompressible materials undergoing large deformation without locking artifacts. We apply it for simulating silicone soft robots with a Poisson ratio close to 0.5. The new approach is based on the mixed finite element method (FEM) using a pressure-displacement formulation; the deviatoric deformation is still handled in a traditional fashion. We support large deformations without volume increase using the corotational formulation of linear elasticity. Stability is ensured by an implicit integration scheme which always reduces to a sparse linear system. For even more deformation accuracy we support higher order simulation through the use of Bernstein-Bézier polynomials.