DYNAMICS AND RESPONSE OF POLYMER-COATED SURFACE-ACOUSTIC-WAVE DEVICES - EFFECT OF VISCOELASTIC PROPERTIES AND FILM RESONANCE
DYNAMICS AND RESPONSE OF POLYMER-COATED SURFACE-ACOUSTIC-WAVE DEVICES - EFFECT OF VISCOELASTIC PROPERTIES AND FILM RESONANCE
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DOI：
10.1021/ac00086a003
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发表时间：
1994-07-15
影响因子：
7.4
通讯作者：
SENTURIA, SD
中科院分区：
文献类型：
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作者：
MARTIN, SJ;FRYE, GC;SENTURIA, SD
研究了聚合物包覆表面声波（SAW）器件对温度变化和聚合物蒸汽吸收的响应。采用微扰方法将速度和衰减响应与SAW产生的薄膜平移和应变模式联系起来。两种不同的薄膜行为机制产生，导致不同的声呐反应。对于玻璃薄膜，位移在整个薄膜厚度上几乎是均匀的，仅在传播方向上发生变化。用于预测该区域的速度和衰减的模型（模型1）可简化为纯弹性膜的熟悉的Tiersten （wohljen）方程。对于弹性（橡胶）薄膜，惯性效应导致剪切位移在整个薄膜上发生相位滞后。考虑这些跨膜位移梯度的模型（模型2）预测了当膜相移达到n pi/2时的特征共振响应，其中n为奇数。将这些模型预测结果与聚异丁烯涂层SAW器件在温度变化和暴露于高蒸汽浓度时的实测响应进行比较。
The response of polymer-coated surface acoustic wave (SAW) devices to temperature changes and polymer vapor absorption is examined. A perturbational approach is used to relate velocity and attenuation responses to film translational and strain modes generated by the SAW. Two distinct regimes of film behavior arise, causing different SAW responses. For glassy films, displacement is nearly uniform across the film thickness, varying only in the direction of propagation. A model developed to predict velocity and attenuation in this regime (model 1), reduces to the familiar Tiersten (Wohltjen) equation for purely elastic films. For elastomeric (rubbery) films, inertial effects cause a phase lag to occur across the film for shear displacements. A model to account for these cross-film displacement gradients (model 2) predicts a characteristic resonant response when the film phase shift reaches n pi/2, where n is an odd integer. These model predictions are compared with measured responses from polyisobutylene-coated SAW devices as temperature is varied and during exposure to high vapor concentrations.