Abstract: A piezoelectric speaker includes: a peripheral rectangular frame having four sides; a central rectangular frame disposed on the peripheral rectangular frame, wherein the central rectangular frame has four corners and four sides, and the four corners are connected to the four sides of the peripheral rectangular frame; four central triangular cantilevers disposed within the central rectangular frame, wherein each of the central triangular cantilevers has a vibrating end and a fixed end opposite to the vibrating end, and each of the fixed ends of the central triangular cantilevers is connected to the four sides of the central rectangular frame, the four vibrating ends of the four central triangular cantilevers are close to each other, and the four central triangular cantilevers have different dimensions of their respective areas defined within the central rectangular frame; and four peripheral triangular cantilevers disposed between the peripheral rectangular frame and the central rectangular frame.

Abstract: The present invention provides a piezoelectric speaker, including: a frame; a cantilever plate actuator disposed on the frame; a spring connected to the frame and the cantilever plate actuator; and a central diaphragm connected to the spring, wherein when the cantilever plate actuator vibrates, the central diaphragm vibrates with the spring.

Abstract: A portable ring-type fluorescence optical system for observing microfluidic channel and an operating method thereof are disclosed. The portable ring-type fluorescence optical system includes a photographic chip, a first polarizer, an objective lens, a ring-type fluorescent light source, a biological sample on a microfluidic chip, a second polarizer and a bottom illumination light source arranged in order from top to bottom. The ring-type fluorescent light source is used to generate a ring-type fluorescent light to the biological sample on the microfluidic chip. The objective lens is used to magnify a fluorescent image of the biological sample on the microfluidic chip to focus on the photographic chip. The first polarizer disposed under the photographic chip and the second polarizer disposed under the biological sample form a non-zero angle to each other to block reflected lights that the biological sample reflects the lights emitted by the bottom illumination light source.

Abstract: A portable ring-type fluorescence optical system for observing microfluidic channel and an operating method thereof are disclosed. The portable ring-type fluorescence optical system includes a photographic chip, a first polarizer, an objective lens, a ring-type fluorescent light source, a biological sample on a microfluidic chip, a second polarizer and a bottom illumination light source arranged in order from top to bottom. The ring-type fluorescent light source is used to generate a ring-type fluorescent light to the biological sample on the microfluidic chip. The objective lens is used to magnify a fluorescent image of the biological sample on the microfluidic chip to focus on the photographic chip. The first polarizer disposed under the photographic chip and the second polarizer disposed under the biological sample form a non-zero angle to each other to block reflected lights that the biological sample reflects the lights emitted by the bottom illumination light source.