Acoustic focusing chip

An acoustic focusing chip irradiated with ultrasonic waves from an acoustic element,

• wherein outer layers serving as both plate surfaces of a plate body including three layers are made of glass,
• wherein an inner layer of the plate body is made of silicon,
• wherein an inlet and an outlet are formed on the outer layer,
• wherein a flow path extending along the plate body in a longitudinal direction is formed to be connected between the inlet and the outlet across a total length of a plate thickness direction in the inner layer,
• wherein a region proximate to the inlet of the flow path becomes an ultrasonic wave application region for receiving irradiation of the ultrasonic waves from a front surface of the plate body,
• wherein the acoustic element is arranged on the plate surface in the ultrasonic wave application region,
• wherein a reflective portion each having reflective surfaces capable of reflecting the ultrasonic waves applied from the acoustic element in contact with the plate surface toward the flow path is arranged such that each of the reflective surfaces is in parallel to the flow path and at the same distance on both sides of the plate body in a width direction for the flow path in the ultrasonic wave application region,
• wherein a heat conductive portion is provided on an opposite side of the flow path with respect to the reflective surfaces of the reflective portion in the width direction of the plate body,
• wherein the reflective surfaces of the reflective portion, the flow path, and the heat conductive portion have a dimension identical to a total thickness of the inner layer in a thickness direction of the plate body,
• wherein the reflective surfaces of the reflective portion are formed by inner spaces formed by filling the inner layer with a gas, and
• wherein a distance between the flow path and the reflective surfaces of the reflective portion in the width direction of the plate body is set to an odd multiple of a one-quarter wavelength of the applied ultrasonic waves.