Cooperative Object Manipulation in Immersive Virtual Environments

MÁRCIO S. PINHO,DOUG A. BOWMAN,CARLA M.D.S. FREITAS 한국HCI학회 2003 한국HCI학회 학술대회 Vol.2003 No.2

Artificial Muscles from Fishing Line and Sewing Thread

Haines, Carter S.,Lima, Má,rcio D.,Li, Na,Spinks, Geoffrey M.,Foroughi, Javad,Madden, John D. W.,Kim, Shi Hyeong,Fang, Shaoli,Jung de Andrade, Mô,nica,Gö,ktepe, Fatma,Gö,ktepe, &Oum American Association for the Advancement of Scienc 2014 Science Vol.343 No.6173

<P><B>Toward an Artificial Muscle</B></P><P>In designing materials for artificial muscles, the goals are to find those that will combine high strokes, high efficiency, long cycle life, low hysteresis, and low cost. Now, <B>Haines <I>et al.</I></B> (p. 868; see the Perspective by <B>Yuan and Poulin</B>) show that this is possible. Twisting high-strength, readily available polymer fibers, such as those used for fishing lines or sewing thread, to the point where they coil up, allowed construction of highly efficient actuators that could be triggered by a number of stimuli.</P>

Temperature-Responsive Tensile Actuator Based on Multi-walled Carbon Nanotube Yarn

Kim, Hyunsoo,Lee, Jae Ah,Sim, Hyeon Jun,Lima, Má,rcio D.,Baughman, Ray H.,Kim, Seon Jeong Springer Berlin Heidelberg 2016 Nano-micro letters Vol.8 No.3

<P>Many temperature indicators or sensors show color changes for materials used in food and medical fields. However, they are not helpful for a color-blind person or children who lack judgment. In this paper, we introduce simply fabricated and more useful low-temperature indicator (~30 °C) for devices that actuates using paraffin-infiltrated multi-walled carbon nanotube (MWCNT) coiled yarn. The density difference of MWCNT yarn provides large strain (~330 %) when heat causes the melted polymer to move. Furthermore, the MWCNT yarn decreases the melting point of paraffin. These properties allow control of the actuating temperature. In addition, mechanical strength was enhanced by MWCNT than previously reported temperature-responsive actuators based on shape memory polymers. This simply fabricated temperature indicator can be applied in latching devices for medical and biological fields.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1007/s40820-016-0084-6) contains supplementary material, which is available to authorized users.</P>

Biothermal sensing of a torsional artificial muscle

Lee, Sung-Ho,Kim, Tae Hyeob,Lima, Má,rcio D.,Baughman, Ray H.,Kim, Seon Jeong The Royal Society of Chemistry 2016 Nanoscale Vol.8 No.6

<P>Biomolecule responsive materials have been studied intensively for use in biomedical applications as smart systems because of their unique property of responding to specific biomolecules under mild conditions. However, these materials have some challenging drawbacks that limit further practical application, including their speed of response and mechanical properties, because most are based on hydrogels. Here, we present a fast, mechanically robust biscrolled twist-spun carbon nanotube yarn as a torsional artificial muscle through entrapping an enzyme linked to a thermally sensitive hydrogel, poly(N-isopropylacrylamide), utilizing the exothermic catalytic reaction of the enzyme. The induced rotation reached an equilibrated angle in less than 2 min under mild temperature conditions (25-37 degrees C) while maintaining the mechanical properties originating from the carbon nanotubes. This biothermal sensing of a torsional artificial muscle offers a versatile platform for the recognition of various types of biomolecules by replacing the enzyme, because an exothermic reaction is a general property accompanying a biochemical transformation.</P>

The Aqueous Extracts of Passiflora alata and Passiflora edulis Reduce Anxiety-Related Behaviors Without Affecting Memory Process in Rats

Paulo R. Barbosa,Samira S. Valvassori,Celso L. Bordignon Jr.,Virginia D. Kappel,M?rcio R. Martins,Elaine C. Gavioli,Jo?o Quevedo,Fl?vio H. Reginatto 한국식품영양과학회 2008 Journal of medicinal food Vol.11 No.2

Several species of Passiflorahave been employed widely as a folk medicine because of sedative and tran-quillizer activities. In this study, we evaluate the effects on anxiety and memory process of two popularly used Passifloraspecies. To this aim, male Wistar rats (weighing 250300 g) were intraperitoneally injected with the aqueous extract of Pas-siflora alataor Passiflora edulis(25, 50, 100, or 150 mg/kg; single injection) 30 minutes prior to the elevated plus-maze test,inhibitory avoidance test, or habituation to an open-field apparatus. The effects of both species of Passiflorawere comparedwith that of diazepam (1 mg/kg), a standard anxiolytic drug. Our findings revealed that, similar to diazepam, the treatmentwith P. alata(100 and 150 mg/kg) and P. edulis(50, 100, and 150 mg/kg) induced anxiolytic-like effects in rats. Memorywas not affected by the treatment with any dose of P. alataor P. edulis, but diazepam disrupted memory process in rats. Phy-tochemical analysis showed that the content of flavonoids of the aqueous extract of P. edulisis almost twice that of P. alata.These differences in contents of flavonoids could explain the lower active doses of the aqueous extract of P. edulisin induc-ing anxiolytic-like effects compared to P. alata. In conclusion, our findings suggest that, distinct from diazepam, the aque-ous extract of both species of Passiflorainduced anxiolytic-like effects in rats without disrupting memory process.

A Reel-Wound Carbon Nanotube Polarizer for Terahertz Frequencies

Kyoung, Jisoo,Jang, Eui Yun,Lima, Má,rcio D.,Park, Hyeong-Ryeol,Robles, Raquel Ovalle,Lepró,, Xavier,Kim, Yong Hyup,Baughman, Ray H.,Kim, Dai-Sik American Chemical Society 2011 NANO LETTERS Vol.11 No.10

<P>Utilizing highly oriented multiwalled carbon nanotube aerogel sheets, we fabricated micrometer-thick freestanding carbon nanotube (CNT) polarizers. Simple winding of nanotube sheets on a U-shaped polyethylene reel enabled rapid and reliable polarizer fabrication, bypassing lithography or chemical etching processes. With the remarkable extinction ratio reaching ∼37 dB in the broad spectral range from 0.1 to 2.0 THz, combined with the extraordinary gravimetric mechanical strength of CNTs, and the dispersionless character of freestanding sheets, the commercialization prospects for our CNT terahertz polarizers appear attractive.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2011/nalefd.2011.11.issue-10/nl202214y/production/images/medium/nl-2011-02214y_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl202214y'>ACS Electronic Supporting Info</A></P>

Ultrastretchable Analog/Digital Signal Transmission Line with Carbon Nanotube Sheets

Lee, Yourack,Joo, Min-Kyu,Le, Viet Thong,Ovalle-Robles, Raquel,Lepró,, Xavier,Lima, Má,rcio D.,Suh, Daniel G.,Yu, Han Young,Lee, Young Hee,Suh, Dongseok American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.31

<P>Stretchable conductors can be used in various applications depending on their own characteristics. Here, we demonstrate simple and robust elastomeric conductors that are optimized for stretchable electrical signal transmission line. They can withstand strains up to 600% without any substantial change in their resistance (<= 10% as is and <= 1% with passivation), and exhibit suppressed charge fluctuations in the medium. The inherent elasticity of a polymeric rubber and the high conductivity of flexible, highly oriented carbon nanotube sheets were combined synergistically, without losing both properties. The nanoscopic strong adhesion between aligned carbon nanotube arrays and strained elastomeric polymers induces conductive wavy folds with microscopic bending of radii on the scale of a few micrometers. Such features enable practical applications such as in elastomeric length-changeable electrical digital and analog signal transmission lines at above MHz frequencies. In addition to reporting basic direct current, alternating current, and noise characterizations of the elastomeric conductors, various examples as a stretchable signal transmission line up to 600% strains are presented by confirming the capability of transmitting audio and video signals, as well as low-frequency medical signals without information distortion.</P>

Tensile actuators of carbon nanotube coiled yarn based on polydiacetylene–pluronic copolymers as temperature indicators

Lee, Hee Uk,Kim, Hyunsoo,Chun, Kyoung-Yong,Kwon, Cheong Hoon,Lima, Má,rcio D,Baughman, Ray H,Kim, Seon Jeong IOP 2016 Smart materials & structures Vol.25 No.7

<P>Most polydiacetylenes (PDAs) have been studied as chromatic sensors or temperature indicators because of their phase transition that is accompanied by a color change from blue to red. Here, we focus on the structural change based on the polydiacetylene phase transition for a temperature-responsive tensile actuator at low temperature using a copolymer composed of PDA and pluronic in a multi-walled carbon nanotube (MWCNT) coiled yarn. In this paper, we do not focus on the general color change phenomenon of PDA. We demonstrate that the volume change of PDA in the MWCNT coiled yarn provides ∼180% tensile strain at low temperature (∼53 °C). Insertion of the pluronic copolymer into the coiled yarn composed of PDA and MWCNT caused the tensile actuation temperature to decrease by ∼6 °C (with tensile actuation of ∼230%) compared to an actuator without pluronic copolymer. Furthermore, we could verify that the large tensile actuation was also predominantly affected by the melting of the nonpolymerized diacetylene (DA) monomer and the pluronic copolymer. MWCNT coiled yarn actuators with PDA-pluronic copolymer can be easily prepared, have a large tensile actuation, and are actuated at low temperature. It could be used as temperature indicators in the food, drugs, and medical fields.</P>

Torsional behaviors of polymer-infiltrated carbon nanotube yarn muscles studied with atomic force microscopy.

Kwon, Cheong Hoon,Chun, Kyoung-Yong,Kim, Shi Hyeong,Lee, Jae-Hyeok,Kim, Jae-Ho,Lima, M?rcio D,Baughman, Ray H,Kim, Seon Jeong RSC Pub 2015 Nanoscale Vol.7 No.6

<P>Torsional behaviors of polymer-infiltrated carbon nanotube (CNT) yarn muscles have been investigated in relation to molecular architecture by using atomic force microscopy (AFM). Two polymers with different stiffnesses, polystyrene (PS) and poly(styrene-b-isoprene-b-styrene) (SIS), were uniformly infiltrated into CNT yarns for electrothermal torsional actuation. The torsional behaviors of hybrid yarn muscles are completely explained by the volume change of each polymer, based on the height and full width at half maximum profiles from the AFM morphological images. The volume expansion of the PS yarn muscle (1.7 nm of vertical change and 22 nm of horizontal change) is much larger than that of the SIS yarn muscle (0.3 nm and 11 nm change in vertical and horizontal directions) at 80 C, normalized by their values at 25 C. We demonstrate that their maximum rotations are consequently 29.7 deg mm(-1) for the PS-infiltrated CNT yarn muscle (relatively larger rotation) and 14.4 deg mm(-1) for the SIS-infiltrated CNT yarn muscle (smaller rotation) at 0.75 V m(-1). These hybrid yarn muscles could be applied in resonant controllers or damping magnetoelectric sensors.</P>

Hybrid Nanomembranes for High Power and High Energy Density Supercapacitors and Their Yarn Application

Lee, Jae Ah,Shin, Min Kyoon,Kim, Shi Hyeong,Kim, Seon Jeong,Spinks, Geoffrey M.,Wallace, Gordon G.,Ovalle-Robles, Raquel,Lima, Má,rcio D.,Kozlov, Mikhail E.,Baughman, Ray H. American Chemical Society 2012 ACS NANO Vol.6 No.1

<P>We report mechanically robust, electrically conductive, free-standing, and transparent hybrid nanomembranes made of densified carbon nanotube sheets that were coated with poly(3,4-ethylenedioxythiophene) using vapor phase polymerization and their performance as supercapacitors. The hybrid nanomembranes with thickness of ∼66 nm and low areal density of ∼15 μg/cm<SUP>2</SUP>exhibited high mechanical strength and modulus of 135 MPa and 12.6 GPa, respectively. They also had remarkable shape recovery ability in liquid and at the liquid/air interface unlike previous carbon nanotube sheets. The hybrid nanomembrane attached on a current collector had volumetric capacitance of ∼40 F/cm<SUP>3</SUP> at 100 V s<SUP>–1</SUP> (∼40 and ∼80 times larger than that of onion-like carbon measured at 100 V s<SUP>–1</SUP> and activated carbon measured at 20 V s<SUP>–1</SUP>, respectively), and it showed rectangular shapes of cyclic voltammograms up to ∼5 V s<SUP>–1</SUP>. High mechanical strength and flexibility of the hybrid nanomembrane enabled twisting it into microsupercapacitor yarns with diameters of ∼30 μm. The yarn supercapacitor showed stable cycling performance without a metal current collector, and its capacitance decrease was only ∼6% after 5000 cycles. Volumetric energy and power density of the hybrid nanomembrane was ∼70 mWh cm<SUP>–3</SUP> and ∼7910 W cm<SUP>–3</SUP>, and the yarn possessed the energy and power density of ∼47 mWh cm<SUP>–3</SUP> and ∼538 W cm<SUP>–3</SUP>.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2012/ancac3.2012.6.issue-1/nn203640a/production/images/medium/nn-2011-03640a_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn203640a'>ACS Electronic Supporting Info</A></P>