本論文主要針對在聲波的作用下,微粒在水中被捕獲在節點區域之討論。藉由施加頻率為2.51MHz及電壓為6Vpp之訊號於壓電元件使其振動並產生聲波,將微粒捕獲在聲束軸上之節點區域內,並透過移動平台移動使微粒脫離節點區域。藉此分析實驗結果中微粒受到聲輻射力作用下,在不同移動速度下掉落時之阻力,進而搭配理論公式分析出作用在微粒上的聲輻射力大小並對其進行比較。;The discussion is focused on how the particles in the water are captured in the pressure node under the influence of sound waves. By applying a signal with 2.51 MHz and 6 Vpp to the piezoelectric element to vibrate and generate ultrasound in the water, the particle is captured in the pressure node on the sound beam axis, and it moved away from the pressure node through the mobile platform. Based on the experimental results, the particle dropped due to the drag force at different moving speeds. Finally, according to this measurement, the estimated acoustic radiation force on the particle is calculated.