Device and method for fabricating locally heterogeneous composite material based on time-frequency regulated surface acoustic waves (SAWs)

A method for fabricating a locally heterogeneous composite material based on time-frequency regulated surface acoustic waves (SAWs), applied to a device comprising a pair of slanted-finger interdigital transducers distributed on two side surfaces of a lithium niobate wafer, a liquid tank placed on a central surface of the lithium niobate wafer between the pair of slanted-finger interdigital transducers and filled with a mixture of a photosensitive liquid, functional particles and a photoinitiator, and an ultraviolet (UV) light source provided directly under the lithium niobate wafer, and the method comprising the following steps:

• step 1:
• mixing the functional particles, the photosensitive liquid and the photoinitiator evenly to obtain the mixture, and adding the mixture into the liquid tank by a pipette;
• step 2:
• inputting periodic time-frequency regulated sinusoidal signals defined by a frequency, a duration, an interval time, and a time difference to the pair of slanted-finger interdigital transducers, such that the pair of slanted-finger interdigital transducers are excited to produce corresponding standing SAWs;
• coupling and allowing the standing SAWs to enter the liquid tank to form a localized acoustic field in the photosensitive liquid;
• and forming, by the functional particles in the photosensitive liquid, a stable array distribution under an acoustic radiation force inside the localized acoustic field;
• and
• step 3:
• turning on the UV light source to photocure the photosensitive liquid and fabricate the locally heterogeneous composite material, wherein the functional particles are fixedly distributed in an array within a localized acoustic field.