Abstract: A series of sinusoidal wavy microchannels with different phase shifts and wavelengths were fabricated on the silicon wafer based on the MEMS technology.Flow frictions in these sinusoidal wavy microchannels were investigated experimentally.Results show that the flow friction in wavy microchannels is higher compared with the smooth straight microchannels with the same hydraulic diameter.Both the phase shift and the wavelength have effect on the flow friction in wavy microchannels.For the microchannels with the same wavelength, the flow friction increases as the phase shift increases.However, the influence of wavelength is complicated.For the microchannels with phase shift of 0, the flow friction normally increases as the wavelength decreases with the exception for the microchannel with the smallest wavelength.For the microchannels with phase shift of π, the flow friction decreases as the wavelength decreases due to the decrease of the throat size in the microchannels.The investigation also shows that as the wavelength decreases, the influence of phase shift on the flow friction decreases.For the wavelength of 0.5 mm, there is little difference in the flow friction between the microchannels with 0 and π phase shifts.

Key words: sinusoidal wavy microchannel, silicon chip, flow friction, phase shift, wavelength

摘要： 硅基正弦波纹微通道在微尺度强化换热、微流体器件中均有重要运用，而目前尚未见有关于其内部流动特性的实验报道。利用标准微机电系统（MEMS）工艺在硅基芯片上加工制成一系列具有不同相位差和周期、当量直径为160 μm的正弦波纹微通道，通过实验研究了其内部流动阻力特性。研究表明：正弦波纹微通道较平直微通道阻力均有增加，且增加幅度与波纹微通道两侧壁的相位差和周期有关。对于周期相同的波纹微通道，两侧壁相位差越大，阻力也越大。对于相位差相同的波纹微通道，周期对阻力的影响则较为复杂：当相位差为0时，呈现出周期越大、阻力越小的趋势（除最小周期通道外）；当相位差为π时，呈现出周期越大、阻力越大的趋势。研究还发现：随着周期减小，相位差对阻力的影响减小，当周期缩短至0.5 mm时，相位差为0和π的波纹微通道内的阻力特性曲线几乎重合。

关键词: 正弦波纹微通道, 硅基芯片, 流动阻力, 相位差, 周期