Polymers and biomolecules moving through disordered media are both interesting from a scientific standpoint and of technological relevance. We are exploring though numerical simulations polymers moving through random and structured substrates. Several key issues we want to explore with the random substrates include how long it takes a polymer to align with an applied field, as well as whether there is a critical disorder strength for the realignment to occur. Also, we are studying how the mobility of the polymers depends on their length and elastic strength, as well as on the strength of the disorder. For polymers moving through structured substrates we are seeking the optimal geometry for separating different polymer lengths. Some geometries we are studying include various types of ratchets. Another approach is to use fractal geometries in order to make a novel type of "fractal ratchet." We are also working on active matter such as swimming bacteria.