Evaluation of Microfluidic Channels With Thin Si Windows and Trapping Structures

We present the fabrication and evaluation of a microchannel with thin Si windows and a trapping structure for injected liquid samples, including an evaluation using tubing methods of polydimethylsiloxane eyelets, and Kovar. Yeast cells and latex particles were observed using a fluorescence microscope under atmospheric conditions and a scanning electron microscope (SEM) under vacuum. As moving and flowing liquid samples cannot be observed for a long time, a trapping structure in the microchannel is required. In our experiment using pole structures under a thin Si window in microchannels to trap liquid samples, we successfully observed them using the SEM under an accelerating voltage of 15 kV and an emission current of 75 μA. This result indicates the possibility of using higher accelerating voltages of electrons for higher observation resolutions at a lower power density of 2.3 kW/cm2. Microfluidic channels with a thin window would be a useful technique for monitoring liquid samples under vacuum. [2020-0367]