We don't think so, a very important property of gravity is that it interacts with everything in the exact same way. This property is behind Einstein's Equivalen

We don't think so, a very important property of gravity is that it interacts with everything in the exact same way. This property is behind Einstein's Equivalence Principle and in turn on our ability to interpret gravity as curvature of spacetime. Metamaterials with special properties under the gravitational interaction would break this. On the other hand, violations of the Equivalence Principle could point into ways of achieving it.