Fabrication of a polymer composite with periodic structure by the use of ultrasonic waves

A polymer composite was fabricated by solidification of a particle suspension in ultrasonic standing waves. Particles of various materials and shapes can be arranged periodically at the nodes of standing waves. A polysiloxane resin is suitable as a host material of the composite, since it is synthesized easily from a solution and it yields a small periodic structure even at a low ultrasonic frequency due to the low sound velocity. This method is useful for fabrication of bulk materials with periodic microstructures. Optical diffraction of a laser beam was observed in a polymer composite made of a polysiloxane resin and acrylic particles.