  The electromagnetic (EM) radiation force-per-length exerted on a pair of
electrically-conducting cylindrical particles of circular and non-circular
cross-sections is examined using a formal semi-analytical method based on
boundary matching in cylindrical coordinates. Initially, the scattering
coefficients of the particle pair are determined by imposing suitable boundary
conditions leading linear systems of equations computed via matrix inversion
and numerical integration procedures. Standard cylindrical (Bessel and Hankel)
wave functions are used and closed-form expressions for the dimensionless
longitudinal and transverse radiation force functions are evaluated assuming
either magnetic (TE) or electric (TM) plane wave incidences. Particle pairs
with smooth and corrugated surfaces are considered and numerical computations
are performed with emphasis on the distance separating their centers of mass,
the angle of incidence of the incident illuminating field and the surface
roughness. Adequate convergence plots confirm the validity of the method to
evaluate the radiation force functions, and the model is adaptable to any
frequency range (i.e. Rayleigh, Mie or geometrical optics regimes). The results
can find potential applications in optical tweezers and other related
applications in fluid dynamics. In addition, the acoustical analogue is
discussed.
