Undergraduate Research Committee

20 February 2006 Undergraduate Research Committee University of Evansville

Dear Committee Members:

Attached is a research proposal requesting funding from your committee. This funding is requested for Summer 2006.

This is a student generated project. To be considered as “student generated,” the student researcher must be responsible for the majority of the concept development, project design, and proposal writing. Student /faculty collaboration, however, is recognized as essential in providing the student with a positive learning experience. Student projects must have a faculty sponsor whose name shall appear on the written proposal. The faculty member will be responsible for the research project.

The students involved in this research meet one of the following four eligibility requirements (specific requirements met are indicated in the signature line): (1) good standing in the Honors Program, (2) GPA of 3.5 or greater, (3) academic scholarship winner (trustee, president, or faculty), or (4) written recommendation from the department chair or dean based on a consensus of the academic department or school (attach a copy of the recommendation).

Thank you for your consideration of our research.

Sincerely:

Evan Hallam (2) Daniel Langenberg (4) 1700 E Walnut St. Rm. 317 400 S. Rotherwood Ave. Rm. 205 S Evansville, IN 47714-1253 Evansville, IN 47714-1530 812-488-3506 812-488-5472 [email protected] [email protected]

Anthony Richardson, PhD Department of EE/CS 812-488-2250 [email protected] The University of Evansville College of Arts and Sciences Department of Electrical Engineering and Computer Science Research Proposal

Title: Electroactive Polymer Criteria for Industrial Active Noise Canceling Transducers

Students: Daniel Langenberg, Evan Hallam

Faculty Sponsor: Anthony Richardson, PhD, Assistant Professor of Electrical Engineering

Summary:

Many industrial settings require moving large amounts of air very quickly. For example, a large industrial motor generates a vacuum in order to remove sewage. The motor uses a blade to compress air and to discharge it into the atmosphere. When the motor is activated, it produces a level of sound comparable to that of a rock concert, and the motor generates several hundred degrees of heat. The common way to lower the volume to OSHA standards is to pass the air through an industrial silencer. There are several industrial models available. The most common method is to employ a silencer on the system’s intake and output. This is similar to the muffler on a car, but can range in size from one foot to more than three stories tall. Since they are made of metal, they can handle high pressure and high temperature situations. However, passive systems are large, bulky, and expensive to design and maintain. Recently, active noise canceling systems have been researched by industry leaders. Such systems use a microphone and speaker combination to cancel unwanted or excessive sound from an environment. Active noise canceling systems would greatly reduce the size, complexity, and, ultimately, the cost of current passive systems. Although this type of system works in theory, typical speaker designs are not capable of enduring high temperature, high pressure environments in practice. In very recent years, electroactive polymers have been researched for various uses such as artificial muscles. These polymers expand and contract in response to applied electrical current. Since electroactive polymers are known to withstand high temperature, high pressure environments, they are suitable for speaker applications in industrial noise cancellation. However, these polymers are still only in the research phase and are not commercially available. Specific guidelines must be determined before investing time and money into electroactive polymer research for specific applications. There are many different kinds of electroactive polymers and they can be used in a number of different configurations. Only a limited amount of research has been conducted with electroactive polymers, much of it being in artificial muscle development. There exists no collection of data on various electroactive polymers and their properties. Thus, this data must be compiled in a useable form in order to determine the exact requirements of an electroactive polymer for use in industrial silencing. It is the intent of this research project to develop a set of specific criteria for an electroactive polymer to be used to drive a speaker for an active sound canceling application. In doing so, a database will be amassed that will include various types of electroactive polymers, their properties, attributes, and possible configurations. This database and an associated computer program will be invaluable to the electroactive polymer research and development communities. Introduction and Literature Review

The movement of air causes an excessive amount of noise and heat, which is nullified through simple, but expensive, techniques. For example, a chemical company might need to remove chemical gas from one room into another, requiring a blower to create the airflow that pushes the chemical to where it needs to go. The problem is that this blower pressurizes a large amount of air, compressing it into a smaller pipe. This compression creates 140 dBA which needs to be silenced to 90 dBA through the use of a large, expensive industrial silencer. These motors also generate large amounts of heat. A 300 horse power motor generating 27 inches of mercury pressure will reach a temperature of 300°F. In theory, active noise cancellation methods can cancel noise at a fraction of the cost of passive methods; however, new speaker material that does not break down at high temperature must be developed.

Of the many forms of electroactive polymers today, the silicone-based dielectric elastomer transducer—also known as electrostatically stricted polymer (ESSP) actuators—produced by SRI shows the most promise in this application. Silicone electroactive polymers can handle strains of up to 300% at over 260°C (500°F) of humidity. The units have been tested for quality at over ten million cycles without any noticeable degradation.

In order to use an electroactive polymer, the A vacuum motor for sewage trucks. All 3 silencers (red and polymer must be sandwiched between two blue “tubes”) are used to lower the noise to below 90 dBA. conductive electrodes.2 When opposite charges are applied to the electrodes they attract. When the same charge is put on both electrodes they repel each other. The pressure exerted by the system can be represented by 2 2 p = er eo E = er eo (V/t) where p = pressure, er = permittivity of free space, eo = relative permittivity (dielectric contact) of the polymer, E = applied electric field, V = applied voltage, and t = film thickness. This material can also be used as a microphone since any external pressure applied to the unit will cause electricity to be generated. 2 2 e = er eo E = er eo (V/t) where e = the amount of electrical energy generated per unit volume of material.1 One must keep in mind that the relationship between diameter and thickness is directly proportional to the 2 2 material before the electric field is applied, d t= d0 t0, where t0 = initial thickness, d0 = initial diameter, t = thickness, and d = the final diameter. This means that when you increase the diameter, you will decrease thickness, and as you decrease the diameter, you will increase thickness.2 Using these properties, Roy Kornbluh, in conjunction with SRI International, used a block of a silicone-based dielectric elastomer connected to a function generator and an amplifier to create a loudspeaker that would reproduce all the audible frequencies at a good fidelity. This quick experiment showed that electroactive polymers were able to handle medium and high frequencies very well but had trouble with lower frequencies. If this material could be adapted

3 to handle lower frequency ranges, a fifteen-foot silencer could be replaced with something as small as three feet. Another use of electroactive polymers is in the robotic and biomedical fields. Since these materials can expand and contract on demand, they are being used as artificial muscles. Last year, the International Society for Optical Engineering (SPIE) held an arm wrestling competition using only electroactive polymer technology. The hope was to create a material that could be used in prosthetic arms with the strength to mimic average users. The previous year’s competition yielded promising results, but no winners. The best arm failed in less than 26 seconds against a 17-year-old female from San Diego. In the introduction to the competition’s web site, the authors stated the ability to develop a winning arm “will require advances in the electroactive polymer field infrastructure including: Analytical tools…”.3 There are many different forms of electroactive polymers available for research today, but tables listing the properties of these materials are hard to come by due to the fact that this is a rapidly evolving field. However, these changes have usually only affected the dielectric constant and its connectors. The general formulas have remained fairly consistent. The ability to refer to a lookup table to see a general formula for a material does not exist, greatly hindering a researcher’s ability to discern which material is needed for particular projects. The development of a database of polymer properties would be an essential tool for further developments in this field. In addition, a computer program that is capable of accessing the database, and given a set of requirements, select the best possible candidates of polymers to use, would speed up the process of polymer selection and may allow researchers to find polymers they had not previously considered. This program may also be capable of simple polymer simulations.

Purpose

The purpose of this research project is to develop a set of specific criteria for an electroactive polymer to be used to drive a speaker for an active sound canceling application in a high temperature, high pressure environment. Although some types of polymers may not be useful in the sound canceling application, all possibilities must be considered. In doing so, a database will be created that will include various types of electroactive polymers, their properties, attributes, and possible configurations. This database and an associated computer program will be invaluable to the electroactive polymer research and development communities. This is the first step towards developing practical sound cancellation technologies using electroactive polymers. A secondary purpose is to produce the essential base research required by the entire electroactive polymer research community for use in other research projects and various applications.

Rationale

Electroactive polymers have the great potential in a variety of applications, but the basic tools needed for development do not exist. Since these tools do not exist, companies are reluctant to invest time or money into a product that might not work the way that they expect. If we can gather all of the data into a concise database, it would be easier to see the potential for the materials. It is also a critical step that needs to be taken before research into practical noise cancellation can begin. This technology could replace expensive, bulky silencers in factories, vehicles, or possibly even replacing heavy magnetically driven speakers. This can save millions

4 of dollars in manufacturing costs, reduce truck emissions (less weight on trucks allow for greater fuel efficiency), reduce noise pollution, and change the way that the speaker industry operates. Electroactive polymers may also have application in various biomedical fields. In order to successfully design these tools, a database must be created containing all of the relevant material properties, formulas, and reaction styles. A program created from this database should be a starting point for electroactive polymer research projects. Researchers will be able to evaluate different polymers, determine which polymer has the properties that they are looking for, and then check to see if their hypothesis about the material is even possible by using the a simulation program. This program may be capable of simple polymer simulations such as determining displacements in certain configurations or finding the maximum frequency response of a polymer.

Hypotheses

Delimitations

These results apply would be in interest to manufactures of systems that create of cancel sound, especially speaker manufacturers, truck manufactures, industrial silencer companies, and blower manufacturers. In addition, the collection of data related to electroactive polymers and their properties are invaluable to the electroactive polymer research community and any others interested in possible applications related to electroactive polymers. Currently, no such collection of data exists for electroactive polymers. Possible applications that could be considered may include artificial muscles, actuators, transducers, electrical current generation, and various biomedical applications, such as heart valves and internal medicine pumps.

Limitations

Definitions

Electroactive polymer: A polymer that reacts in some way to an applied electrical current. These polymers may also be capably of generating a current by movement.3

Electrostatically stricted polymer (ESSP): A silicone-based dielectric elastomer or electroactive polymer. SRI International produces actuators from ESSP technology.

Database: A collection of related entries. In this case, the computerized collection of all known electroactive polymers and their related properties compose the database. dBA: The A scale for decibels. It uses the average audio acuity of humans so that a noise at 30 Hz is heard at the same volume as a noise at 1000 Hz if they are both rated at 120 dBA. Otherwise, the 30 Hz at 120 dB would be comfortable, but the 1000 Hz at 120 dB would be overpowering.6

5 Dielectric: A substance that is highly resistant to flow of electric current, also known as an electrical insulator.5

Pressure: Forces acting on an object. In this case, pressure is measured in inches of Mercury (inHg).

Silencer: Any device used to lower the dB level of a noise source.

Test bed: A configurable model used for testing purposes. In this case, the test bed may consist of a variable frequency generator, amplifier, polymer contacts, and measurement equipment.

Transducer: A device which transforms an input signal—mainly an electrical signal—into motion.4

Methods

Application Basis Set:

A set of requirements must be developed to determine the criteria on which to base the electroactive polymer properties and configuration choices. In the application of active industrial noise cancellation, these requirements may include the range of pressures and temperatures that the polymer must be able to withstand. Since the polymer will be used to drive a speaker, properties such as displacements, voltage requirements, frequency response capabilities, and output amplitudes must be considered when evaluating an electroactive polymer. Although this specific application may span a wide range of requirements, a strict set of criteria will be established based on common industrial noise canceling applications for use in evaluating various types of electroactive polymers. The average requirements for an active industrial noise canceling speaker system are as follows:

Output amplitude: Greater than or equal to 120dBA Displacement: Relative to output and current requirements Current and Voltage requirements: Voltage may be very high, currently no restrictions Frequency Response: 60Hz Temperature: 300º F Pressure: 27 inHg

Material Evaluation:

With this set of requirements, it is now possible to evaluate different types of electroactive polymers, their properties, attributes, and configurations for use in a specific application. Because many different types of electroactive polymers exists, each with different properties and attributes, it is necessary to evaluate each type in different configurations for use in the application basis set. Although it may seem obvious that certain types of electroactive polymers would not be useful in satisfying the application basis set, it is still necessary to evaluate all polymer types and configurations with as much depth is allowed by current research.

6 Data Collection:

Several different kinds of electroactive polymers have been researched. These polymers are known to have certain properties which can be evaluated in application usage. Other types of polymers have not been researched and many more are still hypothetical in nature. These polymers may have some known properties and some hypothetical properties which are believed to exist by researchers. For many electroactive polymers, it is possible to determine immediately whether it will meet the required application basis set. For other polymers, it may be necessary to investigate the electrochemical properties of the material to evaluate different properties or attributes that have not been researched. In as many cases as possible, established properties and proposed formulas, such as those for the displacement of movement, will be tested using samples of the electroactive polymer. Some research organizations and companies are willing to provide samples of the polymers they are working with for testing purposes. Other simple electroactive polymers could be created in the University of Evansville’s Chemistry Department under the direction of Ray Lutgring, chair of the Department of Chemistry. However, only a few types of polymers are readily available for testing and some of these may require test systems that are beyond the capabilities of this project. Most importantly, it is necessary to determine the capabilities of each type of polymer to meet the requirements of the application basis set. In the case of currently unavailable testing capabilities, established, but untested, data will be used. In many instances, especially when dealing with currently hypothetical polymer configurations, this data may be obtained from other researchers working with that specific polymer.

Data Usage:

In evaluating as many different electroactive polymers as possible, a large collection of data relating different types and configurations of polymers to their properties, attributes, and ultimate usability in the application basis set, will be created. This collection will be transformed into a usable database. This designed database will be readily updated with new discoveries, different polymer configuration, or new properties. As stated before, some polymer types or configurations may not have accurate data for various properties. In most cases, these polymers will be identified as unusable for the application basis set. However, these polymers will be flagged as having unknown properties, aiding the electroactive polymer research community in determining what types of polymers should be researched in the future. A computer program will then be created to aide in the search for a suitable electroactive polymer application basis set. This program will analyze each polymer in the database for matches to the application basis set. It may also be necessary to calculate other pieces of information from known properties in the database. For example, the frequency response possible for a given polymer may need to be calculated from the response time and the displacement properties of that polymer. The input to the program will create the database of polymer properties. The output will be a list of polymers, in various configurations, that may possibly meet the application basis set. This narrowed list could then be used to choose a suitable model of an electroactive polymer to research for the purpose of building a speaker suitable for active industrial noise canceling. Although choosing a polymer model is the main goal of the program, it may also be expanded to analyze responses of certain well-known electroactive polymers in given configurations. This would not only be helpful in choosing a suitable polymer for this application, but for other applications as well. Currently, there exist no suitable analytic tools for electroactive polymer researchers. This program, with the associated database, in conjunction

7 with knowledgeable researchers in the electroactive polymer community, could revolutionize research in this area. With a suitable analytical tool researchers would be able to analyze the response of an electroactive polymer, in a given configuration, with given properties, environmental factors and input parameters, without actually building the possibly elaborate and expensive test bed.

8 References:

1. R. Kornbluh, R. Perline, Q. Pei, R. Heydt, S. Stanford, S. Oh, J. Eckerle. “Electroelas- tomers: Applications of Dielectric Elastomer Transducers for Actuation, Generation and Smart Structures, ” Sri International, pp. 2-5, 2001

2. Y. Bar-Cohen. “EAP History, Current Status, and Infrastructure,” in “Electroactive polymer (EAP) Actuators as Artificial Muscles”, ed. Y. Bar-Cohen, Ch. 1, pp. 23. SPIE Press, Bellingham, Washington, 2001

3. Nondestructive Evaluation and Advanced Actuators WorldWide Electroactive Polymer Actuators Webhub, JPL's NDEAA Technologies Lab. September 23, 2005. http://ndeaa.j- pl.nasa.gov/nasa-nde/lommas/electroactive polymer/ELECTROACTIVE POLY- MER-armwrestling.htm

4. “Transducer.” The American Heritage® Dictionary of the English Language. 4th ed. 2000. http://dictionary.reference.com/search?q=transduce

5. “Dielectric.” The American Heritage® Dictionary of the English Language. 4th ed. 2000. http://dictionary.reference.com/search?q=transducer

6. Joe Wolfe. “What is a decibel?” The University of New South Wales. October 10, 2004. http://www.phys.unsw.edu.au/~jw/dB.html

9 Proposed Budget (Itemize in detail as much as possible)

Accounting Code 1000 I. A. Faculty Honorarium $750.00 B. Faculty Summer Stipend ($7,500 max) C. Student Summer Stipend ($3,500 max) $7000.00 D. Student Summer Housing Yes 2000 II. Secretarial and other paid assistance None

III. Travel (for research purposes) not to include travel to None 4000 conferences

5000 IV. Contractual Services None

6000 V. Supplies and Materials

Books and other literary research Electroactive Polymer Actuators as Artificial Muscles - $95.00 Reality, Potential and Challenges Bar-Cohen Electroactive Polymer Electrochemistry $213.00 Lyons Electrical Properties of Polymers (2005) $90.00 Blythe, Bloor Electrical Properties of Polymers (2004) $199.95 Riande, Diaz-Calleja Applications of Electroactive Polymers $191.00 Stienen Electroactive Polymer Actuators and Devices $99.00 Bar-Cohen Electroactive Materials $166.00 Besenhard, Stelzer, Sitte, Gamsjager

Materials Deluxe Bending/Flexing Artificial Muscle Kit from $157.00 Environmental Robotics Inc. Ionic Electroactive Polymer test samples from $20.00 Environments Robotics Inc.

10 Electroactive Polymer Artificial Muscle (EPAM™) $50.00 Sample from Artificial Muscle Inc. Carbon Based Contact Gel from Environmental Robotics $25.00 Inc. Additional Samples of various Electroactive Polymers to $100.00 be purchased from Environmental Robotics Inc, Artificial Muscle Inc., SRI International, NASA’s Jet Propulsion Laboratory, or other research organizations Aqueous Solution of Platinum Ammine Complex for Ion- $95.00 Exchange Polymer Metal Composites (IPMC) from Aldrich Chemical Co. Carbon Nanotubes in solution for IPMC $5.00 To be donated – S&H only Miscellaneous Supplies not available in the Chemistry $50.00 Department (estimated)

Subtotal for Part V $1555.95 7000 VI. Capital Assets (equipment to be purchased off campus) None

Total Budget Requested $9305.95

Note: Every effort will be made to acquire books through interlibrary loan systems. However, many of these books are not commonly found in libraries and will be need to be purchased. If this is the case, used or discounted books will be considered first. This budget includes retail list prices of all books. Also, some research organizations may be willing to supply small samples of the electroactive polymers they are working with at very low costs. Thus, Part V items should be considered a “worst case” estimate of costs.

11 Faculty Biographical Sketch

Name: Anthony (Tony) Richardson Position: Associate Professor of Electrical Engineering

Education

Institution Degree Year Field of Study

University of Kentucky BS 1981 Electrical Engineering Syracuse University MS 1984 Electrical Engineering Duke University PhD 1990 Electrical Engineering

Positions Held

2000 – Present: Assistant and Associate Professor of Electrical Engineering, Director of Electrical Engineering Program. University of Evansville, Evansville, IN. Teach digital and analog electronic circuit analysis and design, assembly and C++ programming, embedded systems and UNIX system programming.

1996-2000: Instructor of Electrical Engineering Technology. Stark State College, Canton, OH. Taught electronics analysis, computer networking and computer administration.

1994-1996: Electronics Instructor and Education Supervisor. ITT Technical Institute, Strongsville, OH. Taught all electronics, computer, physics, and math courses in the curriculum.

1992-1994: Postdoctoral Oceanographer. Scripps Institution of Oceanography, San Diego, CA. Developed several algorithms for use in underwater acoustic signal detection (SONAR). Developed a matched mode acoustic propagation computer simulation program.

1990-1992: Research Assistant Professor. Duke University, Durham, NC. Taught undergraduate courses in linear systems and communication theory. Taught a graduate digital signal processing course. Performed research in acoustic source position estimation.

1986-1990: Research and Teaching Assistant. Duke University, Durham, NC. Performed research in underwater acoustic propagation and source position estimation.

1981-1986: Edison and Advanced Development Engineer. General Electric, Syracuse, NY. Implemented a high resolution bearing estimation algorithm for a passive SONAR system. Designed the controller for a correlation SONAR system. Completed a three year training program (Edison) with a variety of assignments in RADAR and SONAR systems engineering.

12 Role of the students and faculty

This is a student generated research project. The students developed the research question and conducted the literary research with input from Dr. Richardson. The students developed the methods to be used. The students will be responsible for the design, construction, and analysis of the project with assistance from Dr. Richardson as needed.

Timetable for research or project and plan for dissemination of findings

This research project will commence on 22 May 2006 and conclude ten weeks later on 7 August 2006. The purchasing of materials will begin before the actual commencement of research to allow for shipping delays. The major milestone of this project will be the successful development of a set of criteria for an electroactive polymer driven speaker that is suitable for industrial sound cancellation. In developing this set of criteria, collected data of various electroactive polymers will be amassed into a database. A program will be developed to determine the specific attributes and which type(s) of electroactive polymer(s) would be suitable for such an application. A research paper resulting from the finding of this project will be submitted to an academic, professional, or industrial journal such as SPIE’s (The International Society for Optical Engineering) Electroactive Polymer Actuator and Devices (EAPAD) Annual Conference. An abstract of the paper will be submitted to the University of Evansville’s Mathematics, Engineering and Science Undergraduate Research Conference (MESCON) for consideration. The database of various electroactive polymer attributes and configurations would be freely available to any interested parties. This database may, at some point, be placed on the Internet to allow easier access for researchers. Currently, such a collection of data does not exist. The program used to help determine which type of electroactive polymer and under what configuration will be needed for a given application will be developed without a license, and, therefore, will be available in the public domain.

Documentation of Informed Consent