Modeling and Experimental Analysis of the Mass Loading Effect on Micro-Ionic Polymer Actuators Using Step Response Identification

Surface acoustic wave (SAW) sensors form an important class of micro sensors in the microelecto mechanical systems (MEMS) family. Mass loading effect of a sensing medium is one of the prime sensing principles in SAW sensors. Recently we reported mass loading effect of high aspect ratio nano-pillars attached to a SAW resonator. We observed increase in resonance frequency of the SAW resonator in addition to the general mass loading characteristics. We concluded that when the resonance frequency of the pillar is equal to the SAW resonator frequency, the resonance frequency shift caused by mass loading of pillar tends to a negligible value. When such resonating pillars are used as sensing medium in SAW sensors, even a very small change in the dimension of the pillar will offer significant resonance frequency shift. Accordingly, high sensitive SAW sensors can be developed. However in practice it’s quite difficult to manufacture nano-pillars with accurate dimensions such that they resonate with SAW resonator. There is more probability that the pillars may closely resonate with SAW device and offer mass loading. In the present work we have extended our earlier work and performed finite element method (FEM) simulation to study the insight physics of the closely resonating pillars and their effects on acoustic wave propagating on SAW substrate. In this paper we present the discussion on the resonance effects of typical closely resonating pillars on resonance frequency spectrum of the SAW resonator and observations in the pressure wave at the contact surface of the pillar and SAW resonator substrate. It is observed that when the nano-pillars closely resonate with SAW resonator, the pillar oscillations combine with waves propagating in the substrate and introduce beat frequencies. The results and discussion of this paper adds additional information in designing SAW based coupled resonating systems.

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Amino-functionalized graphene electrodes in ionic polymer actuators

10.1063/1.5079342 ◽

2018 ◽

Cited By ~ 1

Author(s):

I. K. Khmelnitsky ◽

N. I. Alekseyev ◽

L. O. Vereschagina ◽

A. P. Broyko ◽

A. V. Lagosh ◽

...

Keyword(s):

Functionalized Graphene ◽

Ionic Polymer ◽

Polymer Actuators

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Hybrid Actuation in Coupled Ionic / Conducting Polymer Devices

MRS Proceedings ◽

10.1557/proc-785-d8.2 ◽

2003 ◽

Vol 785 ◽

Cited By ~ 1

Author(s):

Matthew D. Bennett ◽

Donald J. Leo

Keyword(s):

Conducting Polymer ◽

Smart Materials ◽

Electromechanical Coupling ◽

Performance Metrics ◽

Polymer Membrane ◽

Low Frequencies ◽

Ionic Polymer ◽

Polymer Actuators ◽

Ionic Conducting ◽

Initial Results

ABSTRACTIonic polymer membrane actuators represent a relatively new and exciting entry into the field of smart materials. Several key limitations of these transducers have prevented them from experiencing widespread use, however. For example, the bandwidth of these devices is limited at very low frequencies by characteristic relaxation and at high frequencies by the low elastic modulus of the polymer. In this paper, an overview of the initial results of work with hybrid ionic / conducting polymer actuators is presented. These hybrid actuators are devices that combine the electromechanical coupling of ionic polymer actuators and conducting polymer actuators into one coupled device. Initial results show that these hybrid devices have the potential to offer marked advantages over traditional ionic polymer membrane transducers, including increased stress and strain generation and higher actuation bandwidth. Details of the preparation of these devices and performance metrics are presented and comparisons to baseline materials are made.

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