Chemical Cloaking*

Any object embedded in a chemical gradient will typically distort it. We propose a strategy to hide an object in a gradient by coating it with a chemical reaction-diffusion network which can act as an active cloaking device. By controlling the concentration of some species in its immediate surroundings, the chemical reactions redirect the gradient as if the object was not there. We also show that the energy required to cloak can be extracted from the chemical gradient itself.