不同电极结构的纯横向场激励压电传感器性能研究

Performance Analysis of Pure-lateral-field-excitation Piezoelectric Sensors with Different Electrode Configuration

横向场激励(lateral-field-excitation,LFE)压电传感器因其在液相测量中的优越特性而引起广泛关注。最近的研究表明LFE器件具有纯LFE、伪LFE和准LFE 3种不同的工作模式。为了研究不同电极结构的纯LFE器件的特性,文中在相同的铌酸锂晶体基板上制作了5种不同电极结构的纯LFE压电传感器,并进行了性能测试和对比分析。结果表明:两圈对称螺旋电极结构与单gap电极结构的LFE器件比另外3个LFE器件具有更高的Q值。当传感器从空气中移到水中和从水中移到NaCl溶液中时,谐振频率均减小,而当传感器被从水中移到异丙醇溶液中时,谐振频率增大,其中双间隔电极结构的LFE压电传感器谐振频率变化幅度最大。

Lateral-field-excitation （LFE） sensors have been widely investigated due to their superior performance in liquid sensing applications. Recent studies show that LFE sensors have three different kind of working modes, pure-LFE, quasi-LFE, and pseudo-LFE mode. In order to study the characteristics of pure-LFE piezoelectric sensors, several 4. 5 MHz LFE devices with differ- ent electrode configurations were fabricated and tested. Devices with the two-turn symmetric spiral electrode and the single-gap electrode offer higher Q value than other devices. When the sensing surface of these devices were tested from air to water and from water to NaCI water solution respectively, their resonant frequencies decreased. However, when they were moved from water to isopropanol water solution, the resonant frequencies increased. The device with the dual-gap electrode shows the maximum frequency change compared to other devices.