  We present a novel computational framework for simulating suspensions of
rigid spherical Janus particles in Stokes flow. We show that long-range Janus
particle interactions for a wide array of applications may be resolved using
fast, spectrally accurate boundary integral methods tailored to polydisperse
suspensions of spherical particles. These are incorporated into our rigid body
Stokes platform. Our approach features the use of spherical harmonic expansions
for spectrally accurate integral operator evaluation, complementarity-based
collision resolution, and optimal O(n) scaling with the number of particles
when accelerated via fast summation techniques. We demonstrate the flexibility
of our platform through three key examples of Janus particle systems prominent
in biomedical applications: amphiphilic, bipolar electric and phoretic
particles. We formulate Janus particle interactions in boundary integral form
and showcase characteristic self-assembly and complex collective behavior for
each particle type.
