Microwave Characterization of Carbon Nanotube Yarns For UWB Medical Wireless Body Area Networks

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IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 1

Microwave Characterization of Carbon NanotubeYarns For UWB Medical Wireless

Body Area NetworksSyed Muzahir Abbas, Student Member, IEEE, Oya Sevimli, Member, IEEE,

Michael C. Heimlich, Senior Member, IEEE, Karu P. Esselle, Senior Member, IEEE,B. Kimiaghalam, Javad Foroughi, and Farzad Safaei, Member, IEEE

Abstract—Carbon nanotube (CNT) yarns are novel CNT-basedmaterials that extend the advantages of CNT from the nanoscaleto macroscale applications. In this study, we have modeled CNTyarns as potential data transmission lines. Test structures havebeen designed to measure electrical properties of CNT yarns,which are attached to these test structures using gold paste. DCtesting andmicrowave -parameter measurements have been con-ducted for characterization. The observed frequency independentresistive behavior of the CNT yarn is a very promising indicatorthat this material, with its added values of mechanical resilienceand thermal conductivity, could be invaluable for a range ofapplications such as body area networks. A model is developed forthe CNT yarn, which fits the measured data collected and agreesin general with similar data for non-yarn CNTs.

Index Terms—Carbon nanotube (CNT), CNT yarn, CNT yarnmodel.

I. INTRODUCTION

C ARBON nanotubes (CNTs) have emerged as potentialcandidates for replacement of conventional metals due to

their significant mechanical, electrical, and thermal propertiesand nonoxidizing abilities [1]–[4]. CNTs have been of interest innanoelectronics and nanoantenna applications [5]–[9] since thedensity of CNT composites is about one-fifth of that of copperand around half of that of aluminium. Their thermal conduc-tivity is also about ten times that of copper. Electrical conduc-tivity of CNT composites depends on the properties and loadingof CNTs, the aspect ratio of the CNTs, and the characteristics ofthe conductive network.CNTs hold great promises in a number of related medical

applications because of their remarkable physical properties.The CNT has been used, for example, as the basic underlying

Manuscript received February 20, 2013; revised July 18, 2013; accepted July19, 2013.S. M. Abbas, O. Sevimli, M. C. Heimlich, and K. P. Esselle are with the

Department of Engineering, Macquarie University, North Ryde, N.S.W. 2109,Australia (e-mail: [email protected]; [email protected]; michael.heimlich @mq.edu.au; [email protected]).B. Kimiaghalam and F. Safaei are with the Information and communication

Technology Research Institute, University ofWollongong,Wollongong, N.S.W.2519, Australia (e-mail: [email protected]; [email protected]).J. Foroughi is with the Intelligent Polymer Research Institute, University of

Wollongong, Wollongong, N.S.W. 252, Australia (e-mail: [email protected]).Color versions of one or more of the figures in this paper are available online

at http://ieeexplore.ieee.org.Digital Object Identifier 10.1109/TMTT.2013.2280120

material for an artificial muscle [10] due to their incrediblestrength-to-weight ratio. Electrically, as they are more con-ductive than copper in nanoscales [11], [12], their potentialuse in in-body integrated-circuit-based ultra-wideband (UWB)wireless body area networks (WBANs) would go beyond theartificial muscle to RF/microwave dielectrics, conductors,and sensors [13], suitable for electromagnetic interference(EMI)/electromagnetic compatibility (EMC) applications [14]to transistors [15].Underlying any attempt to integrate the CNT into such ap-

plications is establishing its properties in suitable fabricationtechnologies using compound semiconductor or CMOS. Re-cently, the investigation of the RF/microwave material proper-ties of CNT bundles (on the order of tens of micrometers long)in single- and multi-walled configurations have been the subjectof many studies with somewhat conflicting results [16]. WhileCNT bundles are the underlying building block for many appli-cations, CNT yarns comprised of woven individual nanotubes,can be made to be tens of millimeters in length and as such aresuitable for microelectromechanical systems (MEMs), tunabledielectrics, and related electrical structures at UWB frequen-cies. Establishing the RF/microwavematerial properties of CNTyarns is an essential first step to their use in hybrid manufac-turing technologies.This paper reports the RF/microwave electrical characteriza-

tion of CNT yarns up to 20 GHz with the goal of incorporatingthem in several roles in UWB WBAN. Section II providesan overview on CNT yarn fabrication and their fixturing.Test structures and measurement procedure are discussed inSection III. Results and circuit modeling are presented inSections IV and V, respectively, while Section VI concludesthis paper.

II. CNT YARN FABRICATION AND FIXTURING

A. Yarn Fabrication

The multi-walled carbon nanotube (MWCNT) forest wassynthesized by catalytic chemical vapor deposition (CCVD)using acetylene gas as the carbon source [17]. CNTs, in the300- m-tall forest, typically had diameters of about 10 nm.The yarns were drawn from the forest by pulling and twisting,as described in [18] and [19]. CNT composite yarns can beobtained using a dry spinning process [20]. Processing themusing volatile liquids (like ethanol and methanol) will reduce

0018-9480 © 2013 IEEE


2 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

Fig. 1. SEM micrographs of pristine CNT yarn at: (a) low and (b) higher mag-nification.

the manufacturing irregularities and make them smooth [21],[22].A Leica Stereoscan 440 scanning electron microscope (SEM)

was used for morphological studies of the fibers. SEM micro-graphs of the pristine CNT yarns (Fig. 1) show that the nan-otubes are uniform, and predominantly oriented with a helixangle ( ) 25 . The CNT yarns in our experiments were drawninto 12- and 100- m diameters. The twist is characterized by thehelix angle ( ), which depends directly upon the degree of twistand inversely on the yarn diameter. The number of twists is typ-ically 20000 turns per meter. Earlier, Miao [23] has investigatedelectrical conductivity of CNT yarns, specifically relationshipsbetween number of CNT-to-CNT contact points, yarn surfacetwist angle and porosity, effects of yarn porosity on electricalconductivity, and resistivity of pure CNT yarns.

B. Fixturing

Prepared yarns of 12- and 100- m diameter were attachedusing a two-step procedure. First, the ends were prepared so asto have a planar face by carefully cleaving them perpendicularlyto the major axis of the yarn. Secondly, each yarn was electri-cally andmechanically connected to two launches of a test struc-ture (described in Section III) using gold paste. Since CNTs, asthe building blocks of CNT yarn, are quasi-1-D conductors, spe-cial care was taken to insure that the ends of each yarn had a con-tinuous coating of gold from the end to the test structure launch.Confirmation of the repeatable of the coating was evidenced byconsistency in dc resistance (described in Section IV).A second test structure was prepared as a control for the at-

tachment method and as a potential modeling guide. An enamel-coated wire, approximately 100 m in diameter, was preparedin the same manner as the CNT yarns and fixed to this test struc-ture.

III. TEST STRUCTURES AND MEASUREMENT PROCEDURE

In order to get an indication of the distributed behavior ofthe CNT yarns, a test structure is needed that is a substantialfraction of a wavelength. To this end, test structures supportingyarn lengths of 3500 and 4500 m were fabricated on 10-mil-thick Rogers 4350 ( and ) substrates,patterned with various metal structures, which were previouslyfabricated and used to characterize the Rogers-based materialsystem. A nominal 50- line in this system is more than one-tenth of a wavelength long for frequencies above 5 GHz for the3500- m-long test structure.In addition to the test structure to support yarn attachment,

calibration structures were included on each test vehicle for

Fig. 2. (a) Photograph of the test structure with calibration structures.(b) Close-up of a sample attached to golden pads using gold paste.

TABLE IYARNS’ MEASURED DATA FOR DC

short, open, and thru calibration in both microstrip and coplanarwaveguide configurations. The entire test coupon is shown inFig. 2(a). Yarn samples were attached as shown in Fig. 2(b).An electrical connection was made to the test structure throughground–signal–ground pads at the end. While both coplanar andmicrostrip structures are available on the test coupon, its reusefor this application was limited to the microstrip structures only.Measurements were performed from 50 MHz to 20 GHz

using an HP 8510C. Prior to measurements, a thru-reflect-line(TRL) calibration was performed using the calibration struc-tures on the test coupon.

IV. MEASUREMENTS RESULTS

Testing was done in two phases. First, dc testing was doneto characterize the quality and repeatability of the attachmentand to get a measure of contact resistance. Second, the actualmicrowave measurements were performed. So as to eliminateany potential effects of gold paste diffusion into the CNT yarns,testing was done right after the preparation of the samples andboth tests were performed consecutively.Three samples of 12- and three samples of 100- m yarns

were tested. Three samples of the enamel-coated wire were alsotested.

A. DC Measurements and Analysis

Test results are shown in Table I. The dc resistance of thethru line of the calibration structure was approximately 2 ,which compared to the samples’ resistances is negligible. Theaverage measured resistance of the 12- and 100- m yarns are2.55 k and 170 , respectively. Taking the ratio of the length(l) to diameter (d) as proportional to an equivalent sheet car-rying current along the yarn, the 12- m sample is approximately375-units long and the 100- m sample is 35 units. The sheet re-sistance then for the 12- m yarn is 6.8 /square and the 100- msample is 4.9 square.It would be expected that equivalent CNT densities in the

yarns would yield equivalent sheet resistivities . However,


ABBAS et al.: MICROWAVE CHARACTERIZATION OF CNT YARNS FOR UWB MEDICAL WBANs 3

Fig. 3. Measured of the three 12- m yarn samples on 4500- m substratesshowing very high absorption in transmission and resistance at dc.

contact resistance in CNTs is known to be high [24] andshould scale approximately with the contact area. If the total re-sistance is taken as the sum of a contact resistance that isinversely proportional to the contact area (or to the square of theyarn diameter so that thicker yarns have lower a contact resis-tance) and a sheet resistance that is directly proportional to thelength of the yarn and inversely proportional to the sheet width(or yarn diameter so that thicker yarns give lower resistance andlonger yarns give higher resistance), then an approximate con-tact resistance and sheet resistivity can be calculated using

(1)

(2)

The substitution of the dc resistance values gives 855 and12.3 m as of the 12- and 100- m yarns, respectively.The is a constant 4.5 square for both yarn lengths.

B. Microwave Measurements

Scattering parameters of all samples were measured from50 MHz to 20 GHz. Measured is shown on the Smith chartin Figs. 3–5 for the 12- m yarn, 100- m yarn, and enamel-coated wire, respectively.

V. MODELING

Distributed circuit modeling was performed to ascertain anunderstanding of the material characteristics from the test struc-ture configuration. Previous models have been developed fromfirst principles for single or bundled CNTs [25], [26], which arenot directly applicable to CNT yarns, as they are complex struc-tures made out of CNTs. Therefore, phenomenological models

Fig. 4. Measured for the three 100- m yarn samples on 3500- m sub-strates showing moderate absorption in transmission and resistance at dc.

Fig. 5. Measured for the three 100- m enamel-coated wires samples on3500- m substrates showing low absorption in transmission and negligible dcresistance.

are used here for CNT yarns here to identify their functionalperformance suitable for circuit design.Several factors need to be addressed in the model to repre-

sent nonidealities in the test structure in the electrical model.First, the planar nature of the test structure launch does not pro-vide any facility for repeatable positioning of the yarn or wirein the longitudinal dimension. As such, there is a potential error



Fig. 6. Yarn and wire models of a transmission line with parasitic resistors,capacitor, and inductor for nonideal attachment. (a) transmission line.(b) transmission line.

induced in the effective length of the line, which can be cor-rected by introducing a series inductance or by lengthening thetransmission line. Second, while the transmission structure isclearly a conductor over a ground plane, it is not truly microstripsince the conductor is circular and no physical means of adhe-sion between the conductor and the dielectric substrate is pro-vided directly by the attachment technique beyond yarn/wiretension and gravity. This causes variability in the characteristicimpedance. Third, the high contact resistance of the CNT mustbe accounted for with a fixed resistance, . Finally, the goldpaste on the narrow launch potentially adds a parasitic seriesinductance, , and a shunt capacitance, , or makes at leastone of the ports appear to be complex relative to the calibration.As a method of extracting reasonable material and circuit pa-

rameters from these measurements, two circuit-based modelsusing lumped and distributed elements, representing the effectsmentioned above, were developed using AWR Microwave Of-fice [27]. The model topologies are shown in Fig. 6. Thedistributed model assumes that dielectric losses in the Rogersmaterial are negligible and so a shunt conductance per meter, ,is not included in the modeling of the transmission line.In comparison, the distributed model [27] extracts thecharacteristic impedance , electrical length, and attenuation.The measured data was extracted also using the distributed

model parameters for the enamel-coated wire. Its agree-ment with the measured data is shown in Fig. 7, showingexcellent agreement up to approximately 15 GHz. Thismodel of the wire (Table II) represents a characteristicimpedance of approximately 4128 , which correlates wellto the expected value, not taking into account the enamel,as shown in Fig. 7 when compared to an electromagnetic(EM)-based WIRES models [27] using the finite-elementmethod (FEM). The enamel-coated wire provides a control forthe fixturing procedure and the use of quasi-TEM modelingfor a cylinder-over-ground-plane configuration rather than thetraditional microstrip line-over-ground-plane.Using the same models shown in Fig. 6(b), the 100- m yarn

was modeled. The results for this are shown in Fig. 8 comparingthe measured data to the two models from 0.05 to 20.5 GHz.A least squares fit of the complete set of -parameters for bothreflection and transmission corresponding to this model as com-pared to the measured data was calculated and the worst case

Fig. 7. Enamel-coated wire’s : measured (blue triangle in online version)versus modeled (pink square in online version) versus ideal FEM analysis (redcircle in online version).

TABLE IICNT YARN AND COPPER WIRE COMPARISON AT 5 GHz

USING TRANSMISSION-LINE MODEL

error between the measured and the Fig. 6(b) model results isbetter than 0.25%.As the 12- m yarn is exceedingly lossy for WBAN applica-

tions, the analysis focuses on the 100- m model. The value ofthe each inductor in the models (in Fig. 6) is 0.025 nH. Thisinductor models the extra line length from the calibration refer-ence plane to the CNT yarn (modeled as the transmission line).The value of each is 15 plus a small frequency-depen-dent portion that is proportional to to model the skin depthof the conductive paste connecting the CNT yarn to the refer-ence plane. The value of each shunt capacitor that takes into



Fig. 8. 100- m yarn’s : measured (blue triangle in online version) versusdistributed model (brown diamond in online version) versus lumped model(pink square in online version).

account the extra parasitic capacitance from the paste to groundand fringing capacitance of the discontinuity at the start/termi-nation of the CNT yarn has a value of 0.1 fF. We also addeda small frequency-dependent series reactive part to the50- termination at port 2 to model any asymmetry in the pasteand CNT yard placement. However, the is only about 0.5and contributes only 2% at 10 GHz to the magnitude of theload impedance 50 ; it only improves the fit to the measureddata marginally. De-embedding these from the measured dataleaves the transmission line to have a characteristicimpedance of 124 and an electrical length of 29° at 5 GHz.Next, using the transmission-line model in Fig. 6(a)

for the transmission line and taking the calculated contact re-sistance from the dc values used in the transmissionline model extractions, parameters were fit for the measureddata. The per unit length values for the 100- m-diameter and3500- m-long yarn are given in Table III.The model extracted for the CNT yarn, after taking into

account the nonidealities mentioned above, shows transmis-sion-line characteristic impedance to be nearly identical to thewires of similar diameter (Table II) at 5 GHz. The differencein phase is partially due to the systematic error in this sensitivemeasurement and in the attachment procedure, but this alonecannot account for the difference. The longer electrical lengthfor the yarns as compared to the copper wire is consistentwith CNT yarn conduction theories, which show that thelongitudinal conduction mechanism includes “hopping” fromone CNT filament to another along the yarn axis [1]. Accurateextraction of this phase becomes problematic for the thinneryarns where the resistance is very high. The yarn models (both

and ) differ significantly from the wire modelwith a very high loss for each of the models. The combined

TABLE IIICNT YARN AND COPPER WIRE COMPARISON AT 5 GHz

USING TRANSMISSION-LINE MODEL

effect of the and transmission line ( or )losses account for the entire measured dc resistance and it isfixed, with no significant frequency-dependent contributionover the measured frequencies. The lack of a strong frequencydependent resistance in the yarn is consistent with that foundelsewhere [16].

VI. CONCLUSIONS

CNT yarns were measured at RF/microwave frequencies ina microstrip configuration to ascertain their material proper-ties for UWB WBAN system components as EM surfaces, di-electrics, and conductors. In this first such test for CNT yarns,the data suggests that the CNT yarn performs very much likethe underlying multi-walled CNT bundles. Contact resistanceis relatively high, but good conduction is found within the yarnitself. After accounting for the contact and an effective sheetresistance, the yarn presents a characteristic impedance that iswell approximated through measurement and modeling by acopper wire of similar diameter and attachment method. Thesemodels for the CNT yarn give very good agreement to boththe transmitted and reflected -parameters. The observed fre-quency-independent resistive behavior of the CNT yarn is a verypromising indicator that when the conductivity is improved asa result of ongoing research, this material, with its added valuesof mechanical resilience and thermal conductivity, could be in-valuable for a range of applications such as the body area net-work (BAN).These results suggest that the CNT yarn can be used in mi-

crowave applications in a manner similar to resistive materials,such as NiCr or doped polysilicon. In this configuration, theCNT yarn could act as a probe or conductive structure that is ac-ceptable to biological tissue. New CNT preparation techniques,which include a dopant, have been shown to further reduce theresistivity that may open up additional applications [28].Work continues in this area and is focusing on more accurate

measurements and varying yarn construction factors. To removevariability in the attachment method, the test structure launch isbeing redesigned to cradle the yarn in the transverse and longitu-dinal dimensions. This will have the additional benefit of betterfixing the yarn lengths. Different length yarns will be tested as



well to get a better understanding of phase characteristics. Fi-nally, denser and looser yarns will be tested along with dopedyarns, which have improved dc conductivity.

ACKNOWLEDGMENT

The authors would like to thank M/A-COM TechnologiesNorth Sydney, Sydney, Australia for their gracious supplyof test structures and calibration standard and also thankProf. R. Baughman, University of Texas at Dallas, Dallas,TX, USA, for his continuous support, insights, and also forproviding the CNT forests needed for producing the yarns.

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Syed Muzahir Abbas (S’12) received the B.Sc.degree in electrical (telecommunication) engineeringfrom the COMSATS Institute of Information Tech-nology, Islamabad, Pakistan, in 2006, the M.Sc.degree in computer engineering from the Center forAdvanced Studies in Engineering (CASE), Islam-abad, Pakistan, in 2009, and is currently workingtoward the Ph.D. degree in electronics engineeringat Macquarie University, North Ryde, N.S.W.,Australia.He has been a Transmission Engineer for Alcatel-

Lucent Pakistan and a Lecturer with the Department of Electrical Engineering,COMSATS Institute of Information Technology, Islamabad, Pakistan. His re-search interests include high-impedance surfaces, CNT yarns, and the develop-ment of antennas for UWB and WBAN applications.

Oya Sevimli (M’89–SM’05–S’09–SM’12) receivedthe B.Sc. and M.Sc. degrees in electrical and elec-tronic engineering from Middle East Technical Uni-versity, Ankara, Turkey, in 1981 and 1985, respec-tively, and the Ph.D. degree from Macquarie Univer-sity, North Ryde, N.S.W., Australia, in 2012.She is currently a Research Fellow with the De-

partment of Engineering, Macquarie University. Herresearch interests include nonlinear microwave elec-tronics, noise, electro-thermal modeling, and com-munications technologies.

From 1987 to 2008, she was a Research Scientist with the CSIRO ICT Centre,Sydney, N.S.W., Australia. From 2005 to 2008, she was a Science Leader forMillimetre Wave and Microwave Technologies. Her research has included thedevelopment of millimeter-wave gigabit wireless communication links and thedevelopment of novel monolithic microwave integrated circuits (MMICs) suchas oscillators, bidirectional and low-noise amplifiers, and diode mixers usingInP and GaAs pseudomorphic HEMT (pHEMT) and HBT technologies.



Michael C. Heimlich (M’84–SM’13) received theB.S., M.E., and Ph.D. degrees from the RensselaerPolytechnic Institute, Troy, NY, USA, in 1985, 1987and 1992, respectively, all in electrical engineering.He has held hardware and software engineering

positions with Eastman Kodak, Watkins-Johnson,M/A-COM, IBM Research, Pacific Monolithics,Smartlynx, and AWR, and has been an AdjunctFaculty Member with the New Jersey Institute ofTechnology (NJIT), Newark, NJ, USA. In 2009, hejoined Macquarie University, North Ryde, N.S.W.,

Australia, where he is currently a CoRE Professor of engineering. His currentresearch interests include RF/microwave/millimeter-wave circuits and mate-rials characterization, high-performance circuit and interconnect design andpackaging, electronic design automation (EDA)/computer-aided design (CAD)co-design, and design flow modeling and theory. He has authored over 50papers. He holds two patents as a co-inventor.

Karu P. Esselle (M’92–SM’96) received theB.Sc. degree in electronic and telecommunicationengineering (with First Class Honors) from the Uni-versity of Moratuwa, Moratuwa, Sri Lanka, and theMA.Sc. and Ph.D. degrees in electrical engineeringfrom the University of Ottawa, Ottawa, ON, Canada.He is currently a Professor of engineering

with Macquarie University, North Ryde, N.S.W.,Australia, and the Immediate Past AssociateDean—Higher Degree Research of the Division ofInformation and Communication Sciences, Mac-

quarie University. From 2003 to 2008, he was a member of the DivisionExecutive, and the Head of the Department several times including six monthsin 2011–2112. He has been invited to serve as an international expert/researchgrant assessor by several nationwide research funding bodies overseas in-cluding the Netherlands, Canada, Finland, Hong Kong, and Chile. He has beeninvited by Vice-Chancellors of other universities to assess applications forpromotion to professorial levels. He has also been invited to assess grant appli-cations submitted to Australia’s most prestigious schemes such as AustralianFederation Fellowships and Australian Laureate Fellowships. He has servedin all Macquarie University HDR-related committees at the highest level. Heis the Director of the Centre for Electromagnetic and Antenna Engineering(CELANE) and the Deputy Director of the Research Centre for Microwaveand Wireless Applications, which are parts of the Concentration of ResearchExcellence in Wireless Communications. He leads the Implantable TelemetryTheme of the WiMed Research Centre. In addition to the large number ofinvited conference speeches he has given, he has been an invited speakerof IEEE workshops held in Australia and overseas. The CELANE, whichhe founded, has provided a stimulating research environment for a strongteam of researchers including many research fellows. His mentees have beenawarded six extremely competitive postdoctoral fellowships and many awardsand prizes for their research achievements. Fifteen international experts whoexamined the theses of his recent Ph.D. graduates ranked them in the top 5%or 10%. He has authored approximately 350 research publications and hispapers have been cited over 1800 times. Since 2002, his research team hasbeen involved with research grants, contracts and Ph.D. scholarships worthover 11 million dollars. His industry experience includes full-time employmentas a Design Expert with the Hewlett Packard Laboratory, Palo Alto, CA, USA,and several consultancies for local and international companies, includingCisco Systems, San Jose, CA, USA, Cochlear, Optus Networks, Locata, LasVegas, NV, USA/QX Corporation, ResMed, FundEd, and Katherine-Werke,Rosenheim, Germany, through Peter-Maxwell Solicitors. He was an AssistantLecturer with the University of Moratuwa, a Canadian Government LaboratoryVisiting Postdoctoral Fellow with Health Canada, a Visiting Professor with theUniversity of Victoria, Visiting Research Fellow of the University of WesternAustralia, and a Visiting Scientist with the CSIRO ICT Centre. He is an Editorfor the International Journal of Antennas and Propagation. His research inter-

ests include periodic and electromagnetic bandgap (EBG) structures includingfrequency-selective surfaces and EBG resonator antennas, metamaterials,dielectric-resonator antennas, UWB antennas and systems, broadband andmulti-band antennas, biomedical devices, on-body and through-body wirelesscommunication, millimeter-wave and monolithic microwave integrated circuit(MMIC) devices, antenna and EBG applications in mobile and wirelesscommunication systems, theoretical methods, and lens and focal-plane-arrayantennas for radio astronomy.Prof. Esselle has served on technical program committees or international

committees for many international conferences. He is the Technical ProgramCommittee co-chair of ISAP 2015, APMC 2011 and TENCON 2013 and thepublicity chair of IWAT 2014 and APMC 2000. He is the past chair and cur-rent vice-chair of the IEEE New South Wales (N.S.W.) Microwave Theory andTechniques (MTT)/Antennas and Propagation (AP) Joint Chapter, counsellorof the IEEE Student Branch, Macquarie University, advisor of the IEEE Mi-crowave Theory and Techniques Society (IEEE MTT-S) Chapter, MacquarieUniversity, the Foundation editor-in-chief of MQEC, the past chair of the Ed-ucational Committee of the IEEE N.S.W., and a member of the IEEE N.S.W.Committee. He was the recipient of numerous awards including the 2012 BestPublished Paper Award in Electronic and Telecommunication Engineering fromthe IESL N.S.W. Chapter, 2011 Outstanding Branch Counsellor Award from theIEEE, the 2009 Vice Chancellor’s Award for Excellence in Higher Degree Re-search Supervision, and the 2004 Inaugural Innovation Award for best inventiondisclosure.

Javad Foroughi received the B.S. and M.S. degreesin textile engineering from the Isfahan Universityof Technology, Isfahan, Iran, in 1997, and the Ph.D.degree in material engineering from the Universityof Wollongong, Wollongong, N.S.W., Australia,in 2009. He is currently an ARC Research Fellowwith the Intelligent Polymer Research Institute,University of Wollongong. His research interestsinclude nanomaterials, electromechanical actuators(“artificial muscles”) using inherently conductingpolymers and/or CNTs, bionics and novel fibres

spinning, and the use of these in the development of smart materials andelectronic textiles.

Farzad Safaei (S’95–A’98–M’02) received the de-gree of Bachelor of Engineering (Electronics) degreefrom the University of Western Australia, Crawley,W.A., Australia, and the Ph.D. degree in telecommu-nications engineering from Monash University, Vic-toria, Australia.He is currently the Professor of Telecommunica-

tions Engineering and Managing Director of the In-formation and communication Technology (ICT) Re-search Institute, University of Wollongong, Wollon-gong, N.S.W., Australia. Prior to joining the Univer-

sity of Wollongong, he was the Manager of Internetworking Architecture andServices Section, Telstra Research Laboratories.

B. Kimiaghalam received the B.S. degree in electrical and electronics engi-neering from the Science and Industry (Elm-o-sanaat) University, Tehran, Iran,in 1989, and the M.S. and Ph.D. degrees in electrical engineering from A&TState University, Greensboro, NC, USA, in 1998 and 2001, respectively.From 2006 to 2009, he was the Vice President for Research with QIAU,

Qazvin, Iran. From 2010 to 2011, he conducted research with the Informationand Communication Technology Research (ICTR), Institute of University ofWollongong (UOW), Wollongong, N.S.W., Australia. His research interest in-cludes soft computing, artificial intelligence, optimization, robot navigation, andCNT yarn applications.

Documents

Microwave Characterization of Carbon Nanotube Yarns For UWB Medical Wireless Body Area Networks