公开(公告)号：US08394550B2

公开(公告)日：2013-03-12

申请号：US12807777

申请日：2010-09-14

申请人： Cheng-Chieh Chao ,  Yi Cui ,  Ching-Mei Hsu ,  Young Beom Kim ,  Friedrich B. Prinz

发明人： Cheng-Chieh Chao ,  Yi Cui ,  Ching-Mei Hsu ,  Young Beom Kim ,  Friedrich B. Prinz

IPC分类号： H01M8/10

CPC分类号： H01M8/1213 ,  H01M4/881 ,  H01M4/8867 ,  H01M4/8871 ,  H01M4/9058 ,  H01M8/1253 ,  H01M8/126 ,  Y02E60/525 ,  Y02P70/56

摘要： A nano-patterned membrane electrode assembly (MEA) is provided, which includes an electrolyte membrane layer having a three-dimensional close-packed array of hexagonal-pyramids, a first porous electrode layer, disposed on a top surface of the electrolyte membrane layer that conforms to a top surface-shape of the three-dimensional close-packed array of hexagonal-pyramids, and a second porous electrode layer disposed on a bottom surface of said electrolyte membrane layer that conforms to a bottom surface-shape of the three-dimensional close-packed array of hexagonal-pyramids, where a freestanding nano-patterned MEA is provided.

摘要翻译： 提供了一种纳米图案膜电极组件（MEA），其包括具有三维密集排列的六角锥体的电解质膜层，设置在电解质膜层的顶表面上的第一多孔电极层， 符合六角锥体的立体紧密堆积阵列的顶表面形状，以及设置在所述电解质膜层的底表面上的第二多孔电极层，其符合三维 紧密堆叠的六角形金字塔阵列，其中提供独立的纳米图案MEA。

公开(公告)号：US20110111296A1

公开(公告)日：2011-05-12

申请号：US12944596

申请日：2010-11-11

申请人： Eugene M. Berdichevsky ,  Song Han ,  Yi Cui ,  Rainer J. Fasching ,  Ghyrn E. Loveness ,  William S. DelHagen ,  Mark C. Platshon

发明人： Eugene M. Berdichevsky ,  Song Han ,  Yi Cui ,  Rainer J. Fasching ,  Ghyrn E. Loveness ,  William S. DelHagen ,  Mark C. Platshon

IPC分类号： H01M4/38 ,  H01M4/70 ,  H01M4/66 ,  B05D5/12

CPC分类号： H01M4/134 ,  H01M4/0428 ,  H01M4/1395 ,  H01M4/38 ,  H01M4/661 ,  H01M4/669 ,  H01M4/74 ,  H01M4/742 ,  H01M4/808

摘要： Provided are conductive substrates having open structures and fractional void volumes of at least about 25% or, more specifically, or at least about 50% for use in lithium ion batteries. Nanostructured active materials are deposited over such substrates to form battery electrodes. The fractional void volume may help to accommodate swelling of some active materials during cycling. In certain embodiments, overall outer dimensions of the electrode remain substantially the same during cycling, while internal open spaces of the conductive substrate provide space for any volumetric changes in the nanostructured active materials. In specific embodiments, a nanoscale layer of silicon is deposited over a metallic mesh to form a negative electrode. In another embodiment, a conductive substrate is a perforated sheet with multiple openings, such that a nanostructured active material is deposited into the openings but not on the external surfaces of the sheet.

摘要翻译： 提供了具有至少约25％，或更具体地至少约50％的具有开放结构和分数空隙体积的导电基底，用于锂离子电池。 纳米结构的活性材料沉积在这样的衬底上以形成电池电极。 在循环过程中，分数空隙体积有助于适应一些活性物质的溶胀。 在某些实施例中，电极的整个外部尺寸在循环过程中保持基本相同，而导电衬底的内部开放空间为纳米结构化活性材料中的任何体积变化提供了空间。 在具体实施方案中，将纳米级的硅层沉积在金属网上以形成负电极。 在另一个实施例中，导电衬底是具有多个开口的穿孔片，使得纳米结构的活性材料沉积到开口中而不是在片的外表面上。

公开(公告)号：US20100285358A1

公开(公告)日：2010-11-11

申请号：US12437529

申请日：2009-05-07

申请人： Yi Cui ,  Song Han ,  Mark C. Platshon

发明人： Yi Cui ,  Song Han ,  Mark C. Platshon

IPC分类号： H01M4/58 ,  H01M4/82

CPC分类号： H01M4/134 ,  H01M4/1395 ,  H01M4/366 ,  H01M4/66 ,  H01M4/661 ,  H01M4/663 ,  H01M4/75 ,  H01M10/0525 ,  H01M2004/022 ,  Y10T29/49108

摘要： A lithium ion battery electrode includes silicon nanowires used for insertion of lithium ions and including a conductivity enhancement, the nanowires growth-rooted to the conductive substrate.

摘要翻译： 锂离子电池电极包括用于插入锂离子的硅纳米线，并且包括导电性增强，生长在导电基底上的纳米线。

公开(公告)号：US20100200537A1

公开(公告)日：2010-08-12

申请号：US12653968

申请日：2009-12-17

申请人： Young Beom Kim ,  Yi Cui ,  Ching-Mei Hsu ,  Steve T. Connor ,  Friedrich B. Prinz

发明人： Young Beom Kim ,  Yi Cui ,  Ching-Mei Hsu ,  Steve T. Connor ,  Friedrich B. Prinz

IPC分类号： H01M4/88 ,  C23C14/34

CPC分类号： H01M4/881 ,  C23C14/042 ,  C23C14/185 ,  H01M4/8817 ,  H01M4/8871 ,  H01M4/92

摘要： The current invention provides a method of fabricating nano-pore structured dense Pt electrodes using particle masking and LB deposition methods. The pore size and TPB density are easily tunable by changing initial size of the masking silica particles and the spacing between them. Compared to the solid oxide fuel cell MEAs with porous Pt electrode deposited by conventional DC sputtering method, fuel cell MEAs with the nano structured electrodes fabricated according to the current invention showed thermal and microstructural stability and superior I-V performance at 400˜450° C. Also, EIS spectra showed significant improvement in the oxygen reduction kinetics by increasing the density of charge transfer sites at the TPB. A nearly linear scaling relationship between TPB density and fuel cell performance was also demonstrated.

摘要翻译： 本发明提供使用粒子掩蔽和LB沉积方法制造纳米孔结构致密Pt电极的方法。 通过改变掩模二氧化硅颗粒的初始尺寸和它们之间的间距，可以容易地调节孔径和TPB密度。 与通过常规DC溅射法沉积的具有多孔Pt电极的固体氧化物燃料电池MEA相比，根据本发明制造的具有纳米结构电极的燃料电池MEA在400〜450℃显示出热和微结构稳定性以及优异的IV性能。 ，EIS光谱通过增加TPB上的电荷转移位点的密度，显示出氧还原动力学的显着改善。 TPB密度和燃料电池性能之间几乎线性的缩放关系也得到了证实。

公开(公告)号：US20100093158A1

公开(公告)日：2010-04-15

申请号：US11543353

申请日：2006-10-04

申请人： Charles M. Lieber ,  Yi Cui ,  Xiangfeng Duan ,  Yu Huang

发明人： Charles M. Lieber ,  Yi Cui ,  Xiangfeng Duan ,  Yu Huang

IPC分类号： H01L21/208 ,  H01L21/368

CPC分类号： H01L29/0665 ,  B01J23/50 ,  B01J23/52 ,  B01J23/72 ,  B01J35/0013 ,  B01J37/349 ,  B81C1/0019 ,  B81C1/00206 ,  B82Y10/00 ,  B82Y15/00 ,  B82Y30/00 ,  B82Y40/00 ,  C30B11/00 ,  C30B25/005 ,  C30B29/605 ,  G01N27/4146 ,  G01N33/54373 ,  G11C13/0014 ,  G11C13/0019 ,  G11C13/025 ,  G11C13/04 ,  G11C2213/77 ,  G11C2213/81 ,  H01L21/02521 ,  H01L21/02532 ,  H01L21/0254 ,  H01L21/02543 ,  H01L21/02557 ,  H01L21/0256 ,  H01L21/02573 ,  H01L21/02581 ,  H01L21/02603 ,  H01L21/02606 ,  H01L21/0262 ,  H01L21/02628 ,  H01L21/02631 ,  H01L21/02636 ,  H01L21/02639 ,  H01L21/02645 ,  H01L21/02653 ,  H01L23/53276 ,  H01L29/045 ,  H01L29/0673 ,  H01L29/068 ,  H01L29/16 ,  H01L29/1602 ,  H01L29/18 ,  H01L29/20 ,  H01L29/207 ,  H01L29/22 ,  H01L29/24 ,  H01L29/26 ,  H01L29/267 ,  H01L33/06 ,  H01L33/18 ,  H01L33/20 ,  H01L51/002 ,  H01L51/0048 ,  H01L2924/0002 ,  Y02E10/549 ,  Y02P70/521 ,  Y10S438/962 ,  Y10S977/762 ,  Y10S977/847 ,  Y10S977/858 ,  Y10S977/882 ,  Y10S977/883 ,  Y10S977/892 ,  Y10S977/936 ,  Y10T428/24 ,  H01L2924/00

摘要： A bulk-doped semiconductor that is at least one of the following: a single crystal, an elongated and bulk-doped semiconductor that, at any point along its longitudinal axis, has a largest cross-sectional dimension less than 500 nanometers, and a free-standing and bulk-doped semiconductor with at least one portion having a smallest width of less than 500 nanometers. Such a semiconductor may comprise an interior core comprising a first semiconductor; and an exterior shell comprising a different material than the first semiconductor. Such a semiconductor may be elongated and may have, at any point along a longitudinal section of such a semiconductor, a ratio of the length of the section to a longest width is greater than 4:1, or greater than 10:1, or greater than 100:1, or even greater than 1000:1. At least one portion of such a semiconductor may a smallest width of less than 200 nanometers, or less than 150 nanometers, or less than 100 nanometers, or less than 80 nanometers, or less than 70 nanometers, or less than 60 nanometers, or less than 40 nanometers, or less than 20 nanometers, or less than 10 nanometers, or even less than 5 nanometers. Such a semiconductor may be a single crystal and may be free-standing. Such a semiconductor may be either lightly n-doped, heavily n-doped, lightly p-doped or heavily p-doped. Such a semiconductor may be doped during growth. Such a semiconductor may be part of a device, which may include any of a variety of devices and combinations thereof, and a variety of assembling techniques may be used to fabricate devices from such a semiconductor. Two or more of such a semiconductors, including an array of such semiconductors, may be combined to form devices, for example, to form a crossed p-n junction of a device. Such devices at certain sizes may exhibit quantum confinement and other quantum phenomena, and the wavelength of light emitted from one or more of such semiconductors may be controlled by selecting a width of such semiconductors. Such semiconductors and device made therefrom may be used for a variety of applications.

公开(公告)号：US07619290B2

公开(公告)日：2009-11-17

申请号：US12038794

申请日：2008-02-27

申请人： Charles M. Lieber ,  Hongkun Park ,  Qingqiao Wei ,  Yi Cui ,  Wenjie Liang

发明人： Charles M. Lieber ,  Hongkun Park ,  Qingqiao Wei ,  Yi Cui ,  Wenjie Liang

IPC分类号： H01L27/14 ,  H01L29/82 ,  H01L29/84

CPC分类号： H01L29/0665 ,  B82Y10/00 ,  B82Y15/00 ,  C30B11/00 ,  C30B25/005 ,  C30B29/605 ,  G01N27/4146 ,  G01N33/54373 ,  G01N2610/00 ,  G11C13/0014 ,  G11C13/0019 ,  G11C13/04 ,  G11C2213/17 ,  G11C2213/81 ,  H01L23/53276 ,  H01L29/0669 ,  H01L29/0673 ,  H01L29/16 ,  H01L29/1602 ,  H01L29/1606 ,  H01L29/207 ,  H01L29/267 ,  H01L51/0048 ,  H01L2924/0002 ,  H01L2924/12044 ,  H01L2924/3011 ,  Y10S977/762 ,  Y10S977/957 ,  H01L2924/00

摘要： Electrical devices comprised of nanowires are described, along with methods of their manufacture and use. The nanowires can be nanotubes and nanowires. The surface of the nanowires may be selectively functionalized. Nanodetector devices are described.

公开(公告)号：US07405420B1

公开(公告)日：2008-07-29

申请号：US11541464

申请日：2006-09-29

申请人： H. S. Philip Wong ,  Stefan Meister ,  SangBum Kim ,  Hailin Peng ,  Yuan Zhang ,  Yi Cui

发明人： H. S. Philip Wong ,  Stefan Meister ,  SangBum Kim ,  Hailin Peng ,  Yuan Zhang ,  Yi Cui

IPC分类号： H01L47/00

CPC分类号： H01L27/24 ,  G11C13/0004 ,  Y10S977/94 ,  Y10S977/943

摘要： Chalcogenide-based nanowire memories are implemented using a variety of methods and devices. According to an example embodiment of the present invention, a method of manufacturing a memory circuit is implemented. The method includes depositing nanoparticles at locations on a substrate. Chalcogenide-based nanowires are created at the locations on the substrate using a vapor-liquid-solid technique. Insulating material is deposited between the chalcogenide-based nanowires. Lines are created to connect at least some of the chalcogenide-based nanowires.

摘要翻译： 基于硫族化物的纳米线存储器使用各种方法和装置来实现。 根据本发明的示例性实施例，实现了一种制造存储器电路的方法。 该方法包括在衬底上的位置沉积纳米颗粒。 使用气 - 液 - 固体技术在基板上的位置产生基于硫族化物的纳米线。 绝缘材料沉积在基于硫族化物的纳米线之间。 创建线以连接至少一些基于硫族化物的纳米线。

公开(公告)号：US20070281156A1

公开(公告)日：2007-12-06

申请号：US11386080

申请日：2006-03-21

申请人： Charles Lieber ,  Xiangfeng Duan ,  Yi Cui ,  Yu Huang ,  Mark Gudiksen ,  Lincoln Lauhon ,  Jianfang Wang ,  Hongkun Park ,  Qingqiao Wei ,  Wenjie Liang ,  David Smith ,  Deli Wang ,  Zhaohui Zhong

发明人： Charles Lieber ,  Xiangfeng Duan ,  Yi Cui ,  Yu Huang ,  Mark Gudiksen ,  Lincoln Lauhon ,  Jianfang Wang ,  Hongkun Park ,  Qingqiao Wei ,  Wenjie Liang ,  David Smith ,  Deli Wang ,  Zhaohui Zhong

IPC分类号： D02G3/00

CPC分类号： G11C13/025 ,  B82Y10/00 ,  B82Y15/00 ,  B82Y30/00 ,  C30B11/00 ,  C30B25/00 ,  C30B25/005 ,  C30B29/60 ,  C30B29/605 ,  G01N27/4146 ,  G01N33/54373 ,  G11C11/56 ,  G11C13/0014 ,  G11C13/0019 ,  G11C13/04 ,  G11C2213/17 ,  G11C2213/18 ,  G11C2213/77 ,  G11C2213/81 ,  H01L21/02532 ,  H01L21/0254 ,  H01L21/02543 ,  H01L21/02546 ,  H01L21/02557 ,  H01L21/0256 ,  H01L21/02603 ,  H01L21/02617 ,  H01L21/02628 ,  H01L21/02645 ,  H01L21/02653 ,  H01L23/53276 ,  H01L27/092 ,  H01L29/0665 ,  H01L29/0673 ,  H01L29/0676 ,  H01L29/068 ,  H01L29/125 ,  H01L29/1606 ,  H01L29/2003 ,  H01L29/207 ,  H01L29/267 ,  H01L29/73 ,  H01L29/7781 ,  H01L29/78696 ,  H01L29/861 ,  H01L29/868 ,  H01L31/0352 ,  H01L31/08 ,  H01L33/18 ,  H01L51/0048 ,  H01L51/0595 ,  H01L2924/0002 ,  H01L2924/12044 ,  H01L2924/3011 ,  Y02E10/549 ,  Y10S977/936 ,  Y10S977/938 ,  Y10S977/958 ,  Y10T428/2929 ,  Y10T428/298 ,  H01L2924/00

摘要： The present invention relates generally to sub-microelectronic circuitry, and more particularly to nanometer-scale articles, including nanoscale wires which can be selectively doped at various locations and at various levels. In some cases, the articles may be single crystals. The nanoscale wires can be doped, for example, differentially along their length, or radially, and either in terms of identity of dopant, concentration of dopant, or both. This may be used to provide both n-type and p-type conductivity in a single item, or in different items in close proximity to each other, such as in a crossbar array. The fabrication and growth of such articles is described, and the arrangement of such articles to fabricate electronic, optoelectronic, or spintronic devices and components. For example, semiconductor materials can be doped to form n-type and p-type semiconductor regions for making a variety of devices such as field effect transistors, bipolar transistors, complementary inverters, tunnel diodes, light emitting diodes, sensors, and the like.

公开(公告)号：US07301199B2

公开(公告)日：2007-11-27

申请号：US10196337

申请日：2002-07-16

申请人： Charles M. Lieber ,  Xiangfeng Duan ,  Yi Cui ,  Yu Huang ,  Mark Gudiksen ,  Lincoln J. Lauhon ,  Jianfang Wang ,  Hongkun Park ,  Qingqiao Wei ,  Wenjie Liang ,  David C. Smith ,  Deli Wang ,  Zhaohui Zhong

发明人： Charles M. Lieber ,  Xiangfeng Duan ,  Yi Cui ,  Yu Huang ,  Mark Gudiksen ,  Lincoln J. Lauhon ,  Jianfang Wang ,  Hongkun Park ,  Qingqiao Wei ,  Wenjie Liang ,  David C. Smith ,  Deli Wang ,  Zhaohui Zhong

IPC分类号： H01L29/76 ,  H01L29/94 ,  H01L29/06

CPC分类号： G11C13/025 ,  B82Y10/00 ,  B82Y15/00 ,  B82Y30/00 ,  C30B11/00 ,  C30B25/00 ,  C30B25/005 ,  C30B29/60 ,  C30B29/605 ,  G01N27/4146 ,  G01N33/54373 ,  G11C11/56 ,  G11C13/0014 ,  G11C13/0019 ,  G11C13/04 ,  G11C2213/17 ,  G11C2213/18 ,  G11C2213/77 ,  G11C2213/81 ,  H01L21/02532 ,  H01L21/0254 ,  H01L21/02543 ,  H01L21/02546 ,  H01L21/02557 ,  H01L21/0256 ,  H01L21/02603 ,  H01L21/02617 ,  H01L21/02628 ,  H01L21/02645 ,  H01L21/02653 ,  H01L23/53276 ,  H01L27/092 ,  H01L29/0665 ,  H01L29/0673 ,  H01L29/0676 ,  H01L29/068 ,  H01L29/125 ,  H01L29/1606 ,  H01L29/2003 ,  H01L29/207 ,  H01L29/267 ,  H01L29/73 ,  H01L29/7781 ,  H01L29/78696 ,  H01L29/861 ,  H01L29/868 ,  H01L31/0352 ,  H01L31/08 ,  H01L33/18 ,  H01L51/0048 ,  H01L51/0595 ,  H01L2924/0002 ,  H01L2924/12044 ,  H01L2924/3011 ,  Y02E10/549 ,  Y10S977/936 ,  Y10S977/938 ,  Y10S977/958 ,  Y10T428/2929 ,  Y10T428/298 ,  H01L2924/00

摘要： The present invention relates generally to sub-microelectronic circuitry, and more particularly to nanometer-scale articles, including nanoscale wires which can be selectively doped at various locations and at various levels. In some cases, the articles may be single crystals. The nanoscale wires can be doped, for example, differentially along their length, or radially, and either in terms of identity of dopant, concentration of dopant, or both. This may be used to provide both n-type and p-type conductivity in a single item, or in different items in close proximity to each other, such as in a crossbar array. The fabrication and growth of such articles is described, and the arrangement of such articles to fabricate electronic, optoelectronic, or spintronic devices and components. For example, semiconductor materials can be doped to form n-type and p-type semiconductor regions for making a variety of devices such as field effect transistors, bipolar transistors, complementary inverters, tunnel diodes, light emitting diodes, sensors, and the like.

摘要翻译： 本发明一般涉及亚微电子电路，更具体地涉及纳米尺度制品，包括可以在各种位置和各种级别选择性地掺杂的纳米线。 在一些情况下，制品可以是单晶。 纳米尺寸线可以例如沿其长度或径向掺杂，或者根据掺杂剂的掺杂剂浓度，掺杂剂的浓度或两者掺杂。 这可以用于在单个项目中提供n型和p型导电性，或者在彼此非常接近的不同项目中提供，例如在横杆阵列中。 描述了这种制品的制造和生长，以及这些制品的布置以制造电子，光电子或自旋电子器件和部件。 例如，可以掺杂半导体材料以形成n型和p型半导体区域，用于制造诸如场效应晶体管，双极晶体管，互补反相器，隧道二极管，发光二极管，传感器等的各种器件。

公开(公告)号：US20070048492A1

公开(公告)日：2007-03-01

申请号：US11543337

申请日：2006-10-04

申请人： Charles Lieber ,  Yi Cui ,  Xiangfeng Duan ,  Yu Huang

发明人： Charles Lieber ,  Yi Cui ,  Xiangfeng Duan ,  Yu Huang

IPC分类号： B32B5/00

CPC分类号： H01L29/0665 ,  B01J23/50 ,  B01J23/52 ,  B01J23/72 ,  B01J35/0013 ,  B01J37/349 ,  B81C1/0019 ,  B81C1/00206 ,  B82Y10/00 ,  B82Y15/00 ,  B82Y30/00 ,  B82Y40/00 ,  C30B11/00 ,  C30B25/005 ,  C30B29/605 ,  G01N27/4146 ,  G01N33/54373 ,  G11C13/0014 ,  G11C13/0019 ,  G11C13/025 ,  G11C13/04 ,  G11C2213/77 ,  G11C2213/81 ,  H01L21/02521 ,  H01L21/02532 ,  H01L21/0254 ,  H01L21/02543 ,  H01L21/02557 ,  H01L21/0256 ,  H01L21/02573 ,  H01L21/02581 ,  H01L21/02603 ,  H01L21/02606 ,  H01L21/0262 ,  H01L21/02628 ,  H01L21/02631 ,  H01L21/02636 ,  H01L21/02639 ,  H01L21/02645 ,  H01L21/02653 ,  H01L23/53276 ,  H01L29/045 ,  H01L29/0673 ,  H01L29/068 ,  H01L29/16 ,  H01L29/1602 ,  H01L29/18 ,  H01L29/20 ,  H01L29/207 ,  H01L29/22 ,  H01L29/24 ,  H01L29/26 ,  H01L29/267 ,  H01L33/06 ,  H01L33/18 ,  H01L33/20 ,  H01L51/002 ,  H01L51/0048 ,  H01L2924/0002 ,  Y02E10/549 ,  Y02P70/521 ,  Y10S438/962 ,  Y10S977/762 ,  Y10S977/847 ,  Y10S977/858 ,  Y10S977/882 ,  Y10S977/883 ,  Y10S977/892 ,  Y10S977/936 ,  Y10T428/24 ,  H01L2924/00

摘要： A bulk-doped semiconductor that is at least one of the following: a single crystal, an elongated and bulk-doped semiconductor that, at any point along its longitudinal axis, has a largest cross-sectional dimension less than 500 nanometers, and a free-standing and bulk-doped semiconductor with at least one portion having a smallest width of less than 500 nanometers. Such a semiconductor may comprise an interior core comprising a first semiconductor; and an exterior shell comprising a different material than the first semiconductor. Such a semiconductor may be elongated and may have, at any point along a longitudinal section of such a semiconductor, a ratio of the length of the section to a longest width is greater than 4:1, or greater than 10:1, or greater than 100:1, or even greater than 1000:1. At least one portion of such a semiconductor may a smallest width of less than 200 nanometers, or less than 150 nanometers, or less than 100 nanometers, or less than 80 nanometers, or less than 70 nanometers, or less than 60 nanometers, or less than 40 nanometers, or less than 20 nanometers, or less than 10 nanometers, or even less than 5 nanometers. Such a semiconductor may be a single crystal and may be free-standing. Such a semiconductor may be either lightly n-doped, heavily n-doped, lightly p-doped or heavily p-doped. Such a semiconductor may be doped during growth. Such a semiconductor may be part of a device, which may include any of a variety of devices and combinations thereof, and a variety of assembling techniques may be used to fabricate devices from such a semiconductor. Two or more of such a semiconductors, including an array of such semiconductors, may be combined to form devices, for example, to form a crossed p-n junction of a device. Such devices at certain sizes may exhibit quantum confinement and other quantum phenomena, and the wavelength of light emitted from one or more of such semiconductors may be controlled by selecting a width of such semiconductors. Such semiconductors and device made therefrom may be used for a variety of applications.