Controlling the Frequency Responses of Particles

The frequency responses for various particles in frequency ranges have been reviewed for well control the corresponding frequency responses on related applications. Size effect determines the action range. In general, small particles especially in the nanoscale possess high frequency responses, while coarse particles are sensitive to low frequency ranges. With optimum volume fraction, the reactive near‐field frequency responses from coupling could cause enhanced or retarding far‐field responses. The origin of those responses comes from the polarization of particles in the applied electromagnetic field. The selection of the matrix in which particles are imbedded also determines the response frequency. Modern fabrication technology has progressed to be able to control particle size, shape, and spacing in matrix. To take the advantages of frequency responses from controlled particles, there are plenty of spaces for functional‐designed devices to come out.