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Young Min Song,
Yizhu Xie,
Viktor Malyarchuk,
Jianliang Xiao,
Inhwa Jung,
Ki-Joong Choi,
Zhuangjian Liu,
Hyunsung Park,
Chaofeng Lu, Rak-Hwan Kim,
Rui Li,
Kenneth B Crozier,
Yonggang Huang,
John A Rogers
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ABSTRACT: In arthropods, evolution has created a remarkably sophisticated class of imaging systems, with a wide-angle field of view, low aberrations, high acuity to motion and an infinite depth of field. A challenge in building digital cameras with the hemispherical, compound apposition layouts of arthropod eyes is that essential design requirements cannot be met with existing planar sensor technologies or conventional optics. Here we present materials, mechanics and integration schemes that afford scalable pathways to working, arthropod-inspired cameras with nearly full hemispherical shapes (about 160 degrees). Their surfaces are densely populated by imaging elements (artificial ommatidia), which are comparable in number (180) to those of the eyes of fire ants (Solenopsis fugax) and bark beetles (Hylastes nigrinus). The devices combine elastomeric compound optical elements with deformable arrays of thin silicon photodetectors into integrated sheets that can be elastically transformed from the planar geometries in which they are fabricated to hemispherical shapes for integration into apposition cameras. Our imaging results and quantitative ray-tracing-based simulations illustrate key features of operation. These general strategies seem to be applicable to other compound eye devices, such as those inspired by moths and lacewings (refracting superposition eyes), lobster and shrimp (reflecting superposition eyes), and houseflies (neural superposition eyes).
Nature 05/2013; 497(7447):95-9. · 36.28 Impact Factor
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Tae-Il Kim,
Jordan G McCall,
Yei Hwan Jung,
Xian Huang,
Edward R Siuda,
Yuhang Li,
Jizhou Song,
Young Min Song,
Hsuan An Pao, Rak-Hwan Kim, [......],
Sung Dan Lee,
Il-Sun Song,
Gunchul Shin,
Ream Al-Hasani,
Stanley Kim,
Meng Peun Tan,
Yonggang Huang,
Fiorenzo G Omenetto,
John A Rogers,
Michael R Bruchas
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ABSTRACT: Successful integration of advanced semiconductor devices with biological systems will accelerate basic scientific discoveries and their translation into clinical technologies. In neuroscience generally, and in optogenetics in particular, the ability to insert light sources, detectors, sensors, and other components into precise locations of the deep brain yields versatile and important capabilities. Here, we introduce an injectable class of cellular-scale optoelectronics that offers such features, with examples of unmatched operational modes in optogenetics, including completely wireless and programmed complex behavioral control over freely moving animals. The ability of these ultrathin, mechanically compliant, biocompatible devices to afford minimally invasive operation in the soft tissues of the mammalian brain foreshadow applications in other organ systems, with potential for broad utility in biomedical science and engineering.
Science 04/2013; 340(6129):211-6. · 31.20 Impact Factor
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ABSTRACT: Strategies are presented to achieve ultrathin light-emitting diodes using the technique of epitaxial liftoff in ways that protect the materials from the etchants used for release and tether the devices to the underlying wafer for subsequent transfer printing onto substrates of interest. The results lead to an advanced interconnection scheme and vertical device layout that facilitate electrical contacts and system integration on flexible substrates.
Small 08/2012; 8(20):3123-8. · 8.35 Impact Factor
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Rak-Hwan Kim,
Hu Tao,
Tae-Il Kim,
Yihui Zhang,
Stanley Kim,
Bruce Panilaitis,
Miaomiao Yang,
Dae-Hyeong Kim,
Yei Hwan Jung,
Bong Hoon Kim,
Yuhang Li,
Yonggang Huang,
Fiorenzo G Omenetto,
John A Rogers
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ABSTRACT: Strategies are presented to achieve bendable and stretchable systems of microscale inorganic light-emitting diodes with wireless powering schemes, suitable for use in implantable devices. The results include materials strategies, together with studies of the mechanical, electronic, thermal and radio frequency behaviors both in vitro and in in-vivo animal experiments.
Small 06/2012; 8(18):2812-8. · 8.35 Impact Factor
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Dae-Hyeong Kim,
Nanshu Lu,
Rui Ma,
Yun-Soung Kim, Rak-Hwan Kim,
Shuodao Wang,
Jian Wu,
Sang Min Won,
Hu Tao,
Ahmad Islam, [......],
Ming Li,
Hyun-Joong Chung,
Hohyun Keum,
Martin McCormick,
Ping Liu,
Yong-Wei Zhang,
Fiorenzo G Omenetto,
Yonggang Huang,
Todd Coleman,
John A Rogers
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ABSTRACT: We report classes of electronic systems that achieve thicknesses, effective elastic moduli, bending stiffnesses, and areal mass densities matched to the epidermis. Unlike traditional wafer-based technologies, laminating such devices onto the skin leads to conformal contact and adequate adhesion based on van der Waals interactions alone, in a manner that is mechanically invisible to the user. We describe systems incorporating electrophysiological, temperature, and strain sensors, as well as transistors, light-emitting diodes, photodetectors, radio frequency inductors, capacitors, oscillators, and rectifying diodes. Solar cells and wireless coils provide options for power supply. We used this type of technology to measure electrical activity produced by the heart, brain, and skeletal muscles and show that the resulting data contain sufficient information for an unusual type of computer game controller.
Science 08/2011; 333(6044):838-43. · 31.20 Impact Factor
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Rak-Hwan Kim,
Myung-Ho Bae,
Dae Gon Kim,
Huanyu Cheng,
Bong Hoon Kim,
Dae-Hyeong Kim,
Ming Li,
Jian Wu,
Frank Du,
Hoon-Sik Kim,
Stanley Kim,
David Estrada,
Suck Won Hong,
Yonggang Huang,
Eric Pop,
John A Rogers
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ABSTRACT: This paper describes the fabrication and design principles for using transparent graphene interconnects in stretchable arrays of microscale inorganic light emitting diodes (LEDs) on rubber substrates. We demonstrate several appealing properties of graphene for this purpose, including its ability to spontaneously conform to significant surface topography, in a manner that yields effective contacts even to deep, recessed device regions. Mechanics modeling reveals the fundamental aspects of this process, as well as the use of the same layers of graphene for interconnects designed to accommodate strains of 100% or more, in a completely reversible fashion. These attributes are compatible with conventional thin film processing and can yield high-performance devices in transparent layouts. Graphene interconnects possess attractive features for both existing and emerging applications of LEDs in information display, biomedical systems, and other environments.
Nano Letters 08/2011; 11(9):3881-6. · 13.20 Impact Factor
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Dae-Hyeong Kim,
Nanshu Lu,
Roozbeh Ghaffari,
Yun-Soung Kim,
Stephen P Lee,
Lizhi Xu,
Jian Wu, Rak-Hwan Kim,
Jizhou Song,
Zhuangjian Liu, [......],
Bassel de Graff,
Brian Elolampi,
Moussa Mansour,
Marvin J Slepian,
Sukwon Hwang,
Joshua D Moss,
Sang-Min Won,
Younggang Huang,
Brian Litt,
John A Rogers
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ABSTRACT: Developing advanced surgical tools for minimally invasive procedures represents an activity of central importance to improving human health. A key challenge is in establishing biocompatible interfaces between the classes of semiconductor device and sensor technologies that might be most useful in this context and the soft, curvilinear surfaces of the body. This paper describes a solution based on materials that integrate directly with the thin elastic membranes of otherwise conventional balloon catheters, to provide diverse, multimodal functionality suitable for clinical use. As examples, we present sensors for measuring temperature, flow, tactile, optical and electrophysiological data, together with radiofrequency electrodes for controlled, local ablation of tissue. Use of such 'instrumented' balloon catheters in live animal models illustrates their operation, as well as their specific utility in cardiac ablation therapy. The same concepts can be applied to other substrates of interest, such as surgical gloves.
Nature Material 03/2011; 10(4):316-23. · 32.84 Impact Factor
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Rak-Hwan Kim,
Dae-Hyeong Kim,
Jianliang Xiao,
Bong Hoon Kim,
Sang-Il Park,
Bruce Panilaitis,
Roozbeh Ghaffari,
Jimin Yao,
Ming Li,
Zhuangjian Liu,
Viktor Malyarchuk,
Dae Gon Kim,
An-Phong Le,
Ralph G Nuzzo,
David L Kaplan,
Fiorenzo G Omenetto,
Yonggang Huang,
Zhan Kang,
John A Rogers
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ABSTRACT: Inorganic light-emitting diodes and photodetectors represent important, established technologies for solid-state lighting, digital imaging and many other applications. Eliminating mechanical and geometrical design constraints imposed by the supporting semiconductor wafers can enable alternative uses in areas such as biomedicine and robotics. Here we describe systems that consist of arrays of interconnected, ultrathin inorganic light-emitting diodes and photodetectors configured in mechanically optimized layouts on unusual substrates. Light-emitting sutures, implantable sheets and illuminated plasmonic crystals that are compatible with complete immersion in biofluids illustrate the suitability of these technologies for use in biomedicine. Waterproof optical-proximity-sensor tapes capable of conformal integration on curved surfaces of gloves and thin, refractive-index monitors wrapped on tubing for intravenous delivery systems demonstrate possibilities in robotics and clinical medicine. These and related systems may create important, unconventional opportunities for optoelectronic devices.
Nature Material 11/2010; 9(11):929-37. · 32.84 Impact Factor
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Sang-Il Park,
Yujie Xiong, Rak-Hwan Kim,
Paulius Elvikis,
Matthew Meitl,
Dae-Hyeong Kim,
Jian Wu,
Jongseung Yoon,
Chang-Jae Yu,
Zhuangjian Liu,
Yonggang Huang,
Keh-chih Hwang,
Placid Ferreira,
Xiuling Li,
Kent Choquette,
John A Rogers
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ABSTRACT: We have developed methods for creating microscale inorganic light-emitting diodes (LEDs) and for assembling and interconnecting them into unusual display and lighting systems. The LEDs use specialized epitaxial semiconductor layers that allow delineation and release of large collections of ultrathin devices. Diverse shapes are possible, with dimensions from micrometers to millimeters, in either flat or "wavy" configurations. Printing-based assembly methods can deposit these devices on substrates of glass, plastic, or rubber, in arbitrary spatial layouts and over areas that can be much larger than those of the growth wafer. The thin geometries of these LEDs enable them to be interconnected by conventional planar processing techniques. Displays, lighting elements, and related systems formed in this manner can offer interesting mechanical and optical properties.
Science 09/2009; 325(5943):977-81. · 31.20 Impact Factor
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ABSTRACT: Electronic systems that offer elastic mechanical responses to high-strain deformations are of growing interest because of their ability to enable new biomedical devices and other applications whose requirements are impossible to satisfy with conventional wafer-based technologies or even with those that offer simple bendability. This article introduces materials and mechanical design strategies for classes of electronic circuits that offer extremely high stretchability, enabling them to accommodate even demanding configurations such as corkscrew twists with tight pitch (e.g., 90 degrees in approximately 1 cm) and linear stretching to "rubber-band" levels of strain (e.g., up to approximately 140%). The use of single crystalline silicon nanomaterials for the semiconductor provides performance in stretchable complementary metal-oxide-semiconductor (CMOS) integrated circuits approaching that of conventional devices with comparable feature sizes formed on silicon wafers. Comprehensive theoretical studies of the mechanics reveal the way in which the structural designs enable these extreme mechanical properties without fracturing the intrinsically brittle active materials or even inducing significant changes in their electrical properties. The results, as demonstrated through electrical measurements of arrays of transistors, CMOS inverters, ring oscillators, and differential amplifiers, suggest a valuable route to high-performance stretchable electronics.
Proceedings of the National Academy of Sciences 12/2008; 105(48):18675-80. · 9.68 Impact Factor
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Jongseung Yoon,
Alfred J Baca,
Sang-Il Park,
Paulius Elvikis,
Joseph B Geddes,
Lanfang Li, Rak Hwan Kim,
Jianliang Xiao,
Shuodao Wang,
Tae-Ho Kim,
Michael J Motala,
Bok Yeop Ahn,
Eric B Duoss,
Jennifer A Lewis,
Ralph G Nuzzo,
Placid M Ferreira,
Yonggang Huang,
Angus Rockett,
John A Rogers
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ABSTRACT: The high natural abundance of silicon, together with its excellent reliability and good efficiency in solar cells, suggest its continued use in production of solar energy, on massive scales, for the foreseeable future. Although organics, nanocrystals, nanowires and other new materials hold significant promise, many opportunities continue to exist for research into unconventional means of exploiting silicon in advanced photovoltaic systems. Here, we describe modules that use large-scale arrays of silicon solar microcells created from bulk wafers and integrated in diverse spatial layouts on foreign substrates by transfer printing. The resulting devices can offer useful features, including high degrees of mechanical flexibility, user-definable transparency and ultrathin-form-factor microconcentrator designs. Detailed studies of the processes for creating and manipulating such microcells, together with theoretical and experimental investigations of the electrical, mechanical and optical characteristics of several types of module that incorporate them, illuminate the key aspects.
Nature Material 11/2008; 7(11):907-15. · 32.84 Impact Factor
