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Author

Robert William Filas

Other affiliations: Agere Systems, AT&T
Bio: Robert William Filas is an academic researcher from Alcatel-Lucent. The author has contributed to research in topics: Optical fiber & Coercivity. The author has an hindex of 16, co-authored 32 publications receiving 2264 citations. Previous affiliations of Robert William Filas include Agere Systems & AT&T.

Papers
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Journal ArticleDOI
03 Feb 2000-Nature
TL;DR: It is shown that such an approach can realize much larger scales of integration (in the present case, up to 864 transistors per circuit) and operation speeds of ∼1 kHz in clocked sequential complementary circuits.
Abstract: Thin-film transistors based on molecular and polymeric organic materials have been proposed for a number of applications, such as displays and radio-frequency identification tags. The main factors motivating investigations of organic transistors are their lower cost and simpler packaging, relative to conventional inorganic electronics, and their compatibility with flexible substrates. In most digital circuitry, minimal power dissipation and stability of performance against transistor parameter variations are crucial. In silicon-based microelectronics, these are achieved through the use of complementary logic-which incorporates both p- and n-type transistors-and it is therefore reasonable to suppose that adoption of such an approach with organic semiconductors will similarly result in reduced power dissipation, improved noise margins and greater operational stability. Complementary inverters and ring oscillators have already been reported. Here we show that such an approach can realize much larger scales of integration (in the present case, up to 864 transistors per circuit) and operation speeds of approximately 1 kHz in clocked sequential complementary circuits.

1,291 citations

Patent
29 Nov 1999
TL;DR: In this paper, the authors describe thin film transistor (TFT) devices with source/drain contacts made by a metallo organic deposition (MOD) method wherein a metallorganic compound/metal particulate mixture is deposited to form a base pattern, and the base pattern is then plated with gold.
Abstract: The specification describes thin film transistor (TFT) devices with source/drain contacts made by a metallo organic deposition (MOD) method wherein a metallo organic compound/metal particulate mixture is deposited to form a base pattern, and the base pattern is then plated with gold. The porous, relatively high resistance base pattern is thereby converted to a corrosion resistant, low resistance contact. The plating covers the sidewalls of the base pattern, thus allowing the final channel length to be less than the minimum design rule used for depositing the base pattern.

182 citations

Journal ArticleDOI
TL;DR: In this article, a simple model description of single field effect transistor characteristics was used to design organic complementary circuits ranging in complexity from simple inverters through 48-stage shift registers and three-bit row decoders.
Abstract: We have used a simple model description of single field effect transistor characteristics to design organic complementary circuits ranging in complexity from simple inverters through 48-stage shift registers and three-bit row decoders. The circuits were fabricated using standard silicon photolithographic techniques to define the metal, insulator, and interconnect levels. The ohmic source and drain contacts and part of the interconnect metallization were formed by electroless/immersion deposition of Ni-P/Au on prepatterned TiN. The n-type and p-type organic semicondcutors were evaporated onto these substrates to complete the circuits. Measured circuit characteristics were in reasonable agreement with simulations based on the simple device model.

167 citations

Patent
18 Oct 1999
TL;DR: In this article, an improved process for fabricating emitter structures from nanowires was proposed, where the wires were coated with a magnetic material to allow useful alignment of the wires in the emitter array, and techniques were utilized to provide desirable protrusion of the aligned wires.
Abstract: An improved process for fabricating emitter structures from nanowires, wherein the nanowires are coated with a magnetic material to allow useful alignment of the wires in the emitter array, and techniques are utilized to provide desirable protrusion of the aligned nanowires in the final structure. In one embodiment, nanowires at least partially coated by a magnetic material are provided, the nanowires having an average length of about 0.1 μm to about 10,000 μm. The nanowires are mixed in a liquid medium, and a magnetic field is applied to align the nanowires. The liquid medium is provided with a precursor material capable of consolidation into a solid matrix, e.g., conductive particles or a metal salt, the matrix securing the nanowires in an aligned orientation. A portion of the aligned nanowires are exposed, e.g., by etching a surface portion of the matrix material, to provide desirable nanowire tip protrusion.

130 citations

Patent
10 Sep 2007
TL;DR: In this paper, a micromagnetic device includes a first insulating layer formed above a substrate, a first seed layer formed over a substrate and a first conductive winding layer selectively formed above the seed layer.
Abstract: A micromagnetic device includes a first insulating layer formed above a substrate, a first seed layer formed above the first insulating layer, a first conductive winding layer selectively formed above the first seed layer, and a second insulating layer formed above the first conductive winding layer. The micromagnetic device also includes a first magnetic core layer formed above the second insulating layer, a third insulating layer formed above the first magnetic core layer, and a second magnetic core layer formed above the third insulating layer. The micromagnetic device still further includes a fourth insulating layer formed above the second magnetic core layer, a second seed layer formed above the fourth insulating layer, and a second conductive winding layer formed above the second seed layer and in vias to the first conductive winding layer. The first and second conductive winding layers form a winding for the micromagnetic device.

65 citations


Cited by
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Journal ArticleDOI
05 Feb 2009-Nature
TL;DR: A highly soluble and printable n-channel polymer exhibiting unprecedented OTFT characteristics under ambient conditions in combination with Au contacts and various polymeric dielectrics is reported and all-printed polymeric complementary inverters have been demonstrated.
Abstract: Printed electronics is a revolutionary technology aimed at unconventional electronic device manufacture on plastic foils, and will probably rely on polymeric semiconductors for organic thin-film transistor (OTFT) fabrication. In addition to having excellent charge-transport characteristics in ambient conditions, such materials must meet other key requirements, such as chemical stability, large solubility in common solvents, and inexpensive solution and/or low-temperature processing. Furthermore, compatibility of both p-channel (hole-transporting) and n-channel (electron-transporting) semiconductors with a single combination of gate dielectric and contact materials is highly desirable to enable powerful complementary circuit technologies, where p- and n-channel OTFTs operate in concert. Polymeric complementary circuits operating in ambient conditions are currently difficult to realize: although excellent p-channel polymers are widely available, the achievement of high-performance n-channel polymers is more challenging. Here we report a highly soluble ( approximately 60 g l(-1)) and printable n-channel polymer exhibiting unprecedented OTFT characteristics (electron mobilities up to approximately 0.45-0.85 cm(2) V(-1) s(-1)) under ambient conditions in combination with Au contacts and various polymeric dielectrics. Several top-gate OTFTs on plastic substrates were fabricated with the semiconductor-dielectric layers deposited by spin-coating as well as by gravure, flexographic and inkjet printing, demonstrating great processing versatility. Finally, all-printed polymeric complementary inverters (with gain 25-65) have been demonstrated.

2,769 citations

Journal ArticleDOI
TL;DR: Electronic networks comprised of flexible, stretchable, and robust devices that are compatible with large-area implementation and integrated with multiple functionalities is a testament to the progress in developing an electronic skin akin to human skin.
Abstract: Human skin is a remarkable organ. It consists of an integrated, stretchable network of sensors that relay information about tactile and thermal stimuli to the brain, allowing us to maneuver within our environment safely and effectively. Interest in large-area networks of electronic devices inspired by human skin is motivated by the promise of creating autonomous intelligent robots and biomimetic prosthetics, among other applications. The development of electronic networks comprised of flexible, stretchable, and robust devices that are compatible with large-area implementation and integrated with multiple functionalities is a testament to the progress in developing an electronic skin (e-skin) akin to human skin. E-skins are already capable of providing augmented performance over their organic counterpart, both in superior spatial resolution and thermal sensitivity. They could be further improved through the incorporation of additional functionalities (e.g., chemical and biological sensing) and desired properties (e.g., biodegradability and self-powering). Continued rapid progress in this area is promising for the development of a fully integrated e-skin in the near future.

1,950 citations

Journal ArticleDOI
TL;DR: Integration of organic transistors and rubber pressure sensors, both of which can be produced by low-cost processing technology such as large-area printing technology, will provide an ideal solution to realize a practical artificial skin.
Abstract: It is now widely accepted that skin sensitivity will be very important for future robots used by humans in daily life for housekeeping and entertainment purposes Despite this fact, relatively little progress has been made in the field of pressure recognition compared to the areas of sight and voice recognition, mainly because good artificial “electronic skin” with a large area and mechanical flexibility is not yet available The fabrication of a sensitive skin consisting of thousands of pressure sensors would require a flexible switching matrix that cannot be realized with present silicon-based electronics Organic field-effect transistors can substitute for such conventional electronics because organic circuits are inherently flexible and potentially ultralow in cost even for a large area Thus, integration of organic transistors and rubber pressure sensors, both of which can be produced by low-cost processing technology such as large-area printing technology, will provide an ideal solution to realize a practical artificial skin, whose feasibility has been demonstrated in this paper Pressure images have been taken by flexible active matrix drivers with organic transistors whose mobility reaches as high as 14 cm2/V·s The device is electrically functional even when it is wrapped around a cylindrical bar with a 2-mm radius

1,804 citations