Alexander Will

Bio: Alexander Will is an academic researcher from Michigan State University. The author has contributed to research in topics: RYR1 & Calcium. The author has an hindex of 1, co-authored 1 publications receiving 170 citations.

A dynamic model for ionic polymer-metal composite sensors

Abstract: A dynamic, physics-based model is presented for ionic polymer–metal composite (IPMC) sensors. The model is an infinite-dimensional transfer function relating the short-circuit sensing current to the applied deformation. It is obtained by deriving the exact solution to the governing partial differential equation (PDE) for the sensing dynamics, where the effect of distributed surface resistance is incorporated. The PDE is solved in the Laplace domain, subject to the condition that the charge density at the boundary is proportional to the applied stress. The physical model is expressed in terms of fundamental material parameters and sensor dimensions and is thus scalable. It can be easily reduced to low-order models for real-time conditioning of sensor signals in targeted applications of IPMC sensors. Experimental results are provided to validate the proposed model.

Energy harvesting from base excitation of ionic polymer metal composites in fluid environments

Abstract: In this paper, we analytically and experimentally study the energy harvesting capability of submerged ionic polymer metal composites?(IPMCs). We consider base excitation of an IPMC strip that is shunted with an electric impedance and immersed in a fluid environment. We develop a modeling framework to predict the energy scavenged from the IPMC vibration as a function of the excitation frequency range, the constitutive and geometric properties of the IPMC, and the electric shunting load. The mechanical vibration of the IPMC strip is modeled through Kirchhoff?Love plate theory. The effect of the encompassing fluid on the IPMC vibration is described by using a linearized solution of the Navier?Stokes equations, that is traditionally considered in modeling atomic force microscope cantilevers. The dynamic chemo-electric response of the IPMC is described through the Poisson?Nernst?Planck model, in which the effect of mechanical deformations of the backbone polymer is accounted for. We present a closed-form solution for the current flowing through the IPMC strip as a function of the voltage across its electrodes and its deformation. We use modal analysis to establish a handleable expression for the power harvested from the vibrating IPMC and to optimize the shunting impedance for maximum energy harvesting. We validate theoretical findings through experiments conducted on IPMC strips vibrating in aqueous environments.

A review on IPMC material as actuators and sensors: Fabrications, characteristics and applications

Abstract: In this paper we present a comprehensive review of ionic polymer metal composite (IPMC) covering fundamentals of IPMC; from fabrication processes to control and applications. IPMC is becoming an increasingly popular material among scholars, engineers and scientists due to its inherent property of low activation voltage, large bending strain, i.e., transformation electrical energy to mechanical energy, and properties to be used as bidirectional material, i.e., it can be used as actuators and sensors. Among the diversity of electro active polymers (EAPs), recently developed IPMCs are good candidates for use in bio-related application because of their biocompatibility. Yet, the challenge remains in controlling a somewhat complicated material as mechanical, electrical and chemical properties interact with each other in the ionic polymer. Several IPMC fabrication processes, their mechanical characteristics and performance, a number of recent IPMC applications and pertaining mathematical modeling have been reported in this paper. Also we have attempted to present concisely the control of IPMC and effects of various factors in the performance of IPMC. The applications of IPMC have been growing, and recently more sophisticated IPMC actuator applications have been performed. This indicates that the IPMC actuators hold potential for more sophisticated control application. Extensive references are provided for more indepth explanation.

Ionic polymer–metal composite mechanoelectrical transduction: review and perspectives

Abstract: This paper presents a comprehensive review of the use of ionic polymer-metal composite (IPMC) materials as mechanoelectrical transducers. Recently increasing emphasis has been put on the research of IPMCs as displacement or velocity sensors for various applications. This has resulted in various theories and models to describe the mechanoelectrical transduction phenomenon. The paper gives an overview of the proposed transduction principles, developed models and the latest applications. In more detail, the history of IPMC materials, the physics and the electrochemistry behind the mechanoelectrical transduction, different black-box and gray-box models, and novel real-world mechatronics-related applications are discussed throughout the paper. However, despite the latest advancements in the research of IPMC transduction, there is still a certain amount of controversy regarding some of the IPMC sensorial properties. For instance, it has been noticed by several authors that there is a signal delay when bending an IPMC. The general understanding of the physical principles about regular IPMC mechanoelectrical transduction is rather good. In the last section of the paper novel results are presented for copper-coated IPMC materials. Apparently the electrochemistry behind the transduction for copper-coated IPMCs is significantly different. Besides ionic diffusion, chemical reactions on the electrodes also occur and dominate the actuation process. Experimental results show some promising opportunities for designing new copper-coated IPMC-based sensors. Copyright © 2010 Society of Chemical Industry

Underwater energy harvesting from a heavy flag hosting ionic polymer metal composites

Abstract: In this paper, we analyze underwater energy harvesting from the flutter instability of a heavy flag hosting an ionic polymer metal composite (IPMC). The heavy flag comprises a highly compliant membrane with periodic metal reinforcements to maximize the weight and minimize the bending stiffness, thus promoting flutter at moderately low flow speed. The IPMC is mechanically attached to the host flag and connected to an external load. The entire structure is immersed in a mean flow whose intensity is parametrically varied to explore the onset of flutter instability along with the relation between the vibration frequency and the mean flow speed. Manageable theoretical models for fluid-structure interaction and IPMC response are presented to inform the harvester design and interpret experimental data. Further, optimal parameters for energy scavenging maximization, including resistive load and flow conditions, are identified.

A Review of Ionic Polymeric Soft Actuators and Sensors

Abstract: This article reviews properties and characteristics of soft ionic polymer–metal nanocomposites as soft biomimetic multifunctional distributed robotic materials, soft actuators, soft sensors, soft transducers and energy harvesters, and artificial muscles. After presenting some fundamental properties of biomimetic distributed nanosensing and nanoactuation of ionic polymer–metal composites, the discussion extends to some recent advances in manufacturing techniques, 3D fabrication of these soft actuators and sensors and some recent modeling and simulations, sensing and transduction, and product development. The relationships between the properties and their connection to the characteristics of soft actuators and sensors are also discussed.