  Active Brownian particles (ABPs) are termed out to be a successful way of
modeling the moving microorganism on the substrate. In recent studies, it is
shown that such organisms can sense the characteristics of the substrate.
Motivated by such work, we studied the dynamics and the steady state of ABP
moving on a substrate with space-dependent activity. On the substrate, some
regions are marked as high in activity, and other regions are such that
particles behave as passive Brownian particles. The system is studied in two
dimensions with step, sigmoid, Gaussian and cone shape distribution of activity
profile on the substrate. The whole interface of the activity profile is
symmetrically divided into two regions. This lead to the flow of particles from
the active region to the passive region. The final steady state of particle
density profile, polarisation and flux very much follows the structure of the
inhomogeneous activity and the density in high activity region is lower,
maximum at the interface and nearly constant with mean density in the passive
region. Further, the steady state density profile for various shapes and
designs on two-dimensional substrates. Hence the collection of ABPs on an
inhomogeneous substrate can mimic the inhomogeneity of the substrate.
