In-situ, Remote Query Chemical Sensors Based On Magnetoelastic Thick Films

这项提议寻求支持开发和应用一种新的远程查询传感器技术，该技术以自支撑磁弹性厚膜的共振频率变化为基础。这项工作建立在化学传感器的基础上，补充和帮助扩展了共同PI积极参与的面向化学传感器的研究。磁弹性传感器由磁致伸缩、磁弹性非晶态金属玻璃的带状厚膜组成[1]。作为对交流磁场的响应，传感器有效地将磁能转化为弹性能，而弹性能反过来又使传感器机械变形。这种机械变形表现为机械共振，其频率与传感器的长度成反比。最近已经证明，磁弹性传感器的谐振频率会随着几个不同的环境参数而变化，包括压力、温度、粘度、界面分子键，以及非常重要的是，当与质量变化的化学响应层[3]化学分析物浓度结合使用时。磁弹性传感器在远程查询化学传感方面的应用已经使用葡萄糖响应聚合物进行了演示[4]。测量了磁弹性传感器在小于0.9 ng/mm~2的不同表面质量载荷下的谐振频率变化。本研究选择了三种类型的微孔薄膜，为控制气体在微孔中的吸附和/或吸收提供了广泛的表面化学成分。通过控制孔径和表面化学，我们可以调节磁弹性传感器对混合物中给定化合物的选择性，该混合物可能包含许多不同的溶质和溶剂分子。

This proposal seeks support for the development and application of a new remote query sensor technology based on changes in the resonant frequency of free-standing magnetoelastic thick films. The work builds upon, complements, and helps extend the chemical sensor oriented research the co-PI's are actively involved with.Magnetoelastic sensors are comprised of ribbon-shaped thick-films of magnetostrictive, magnetoelastic amorphous metallic glass [1]. In response to an ac magnetic field the sensors efficiently translate magnetic energy into elastic energy which, in turn, acts to mechanically deform the sensor. This mechanical deformation demonstrates a mechanical resonance the frequency of which is inversely proportional to the length of the sensor. It has recently been demonstrated [2] that the resonant frequency of a magnetoelastic sensor shifts in response to several different environmental parameters including pressure, temperature, viscosity, inter-facial molecular bond and, very importantly, when used in combination with a mass changing, chemically responsive layer [3] chemical analyte concentrations. Applications of magnetoelastic sensors to remote query chemical sensing has been demonstrated using a glucose responding polymer [4]. Changes in the resonant frequency of a magnetoelastic sensor have been measured in response to differential surface mass loadings below 0.9 ng/mm2. Three types of microporous thin-films were chosen for this study, providing a broad range of surface chemistries for controlling the adsorption and/or absorption of gas into the micropores. By controlling the pore size as well as the surface chemistry, we can tune the selectivity of the magnetoelastic sensor to a given compound in a mixture that may contain numerous different solute and solvent molecules.