Fluidic device and method for controlling fluidic device

A method for controlling a fluidic device that captures a fine particle in a fluid flowing through a channel extending along a first axis,

• the fluidic device including an ultrasonic transmission part that is disposed at the channel and transmits an ultrasonic wave into the channel along a second axis orthogonal to the first axis in response to input of a drive signal,
• the fluidic device further including a first circuit, a second circuit, and a processor for controlling execution of the method, and
• the method for controlling the fluidic device comprising:
• controlling the ultrasonic transmission part via at least one of the first circuit or the second circuit;
• controlling the second circuit to change a drive frequency of the drive signal within a predetermined range;
• controlling the second circuit to drive the ultrasonic transmission part by changing the drive frequency of the drive signal within the predetermined range;
• controlling the second circuit to measure impedance of the ultrasonic transmission part at a time when the ultrasonic transmission part is driven while changing the drive frequency of the drive signal within the predetermined range;
• specifying a drive frequency at which the impedance is a local maximum;
• setting the drive frequency at which the impedance is the local maximum as a first drive frequency;
• and
• controlling the first circuit to input the drive signal of the first drive frequency to the ultrasonic transmission part.