Evander Mikael, Lenshof Andreas, Laurell Thomas, Nilsson Johan
The Department of Electrical Measurements, Lund University, P.O. Box 118, 211 00 Lund, Sweden.
Anal Chem. 2008 Jul 1;80(13):5178-85. doi: 10.1021/ac800572n. Epub 2008 May 20.
Acoustophoresis in microfluidic structures has primarily been reported in silicon microfabricated devices. This paper demonstrates, for the first time, acoustophoresis performed in isotropically etched glass chips providing a performance that matches that of the corresponding silicon microdevices. The resonance mode characteristics of the glass chip were equal to those of the silicon chip at its fundamental resonance. At higher order resonance modes the glass chip displays resonances at lower frequencies than the silicon chip. The cross-sectional profiles of acoustically focused particle streams are also reported for the first time, displaying particles confined in a vertical band in the channel center for both glass and silicon chips. A particle extraction efficiency of 98% at flow rates up to 200 microL/min (2% particle concentration) is reported for the glass chip at the fundamental resonance. The glass and silicon chips displayed equal particle extraction performance when tested for increasing particle concentrations of 2-15%, at a flow velocity of 12.9 cm/s for the glass chip and 14.8 cm/s for the silicon chip.
微流控结构中的声泳现象主要在硅微加工器件中得到报道。本文首次展示了在各向同性蚀刻玻璃芯片中进行的声泳，其性能与相应的硅微器件相当。玻璃芯片的共振模式特性在其基模共振时与硅芯片相同。在高阶共振模式下，玻璃芯片的共振频率低于硅芯片。本文还首次报道了声聚焦粒子流的横截面轮廓，显示玻璃芯片和硅芯片中的粒子都被限制在通道中心的垂直带中。在基模共振时，玻璃芯片在流速高达200微升/分钟（粒子浓度为2%）时的粒子提取效率为98%。当测试粒子浓度增加到2%-15%时，玻璃芯片的流速为12.9厘米/秒，硅芯片的流速为14.8厘米/秒，此时玻璃芯片和硅芯片的粒子提取性能相同。
