-
[show abstract]
[hide abstract]
ABSTRACT: A smart meter is essential for realizing the smart grid. In order to further reduce the energy loss in the power grid, an extremely fine-grain power monitoring system is desirable and it will require an enormous number of low-cost power meters. Existing power meters, however, do not meet the cost and size requirements. On the other hand, organic devices on flexible films have great potential to realize low-cost power meters. In this paper, a 100-V AC power meter based on System-on-a-Film (SoF) concept is demonstrated.
Solid-State Circuits Conference Digest of Technical Papers (ISSCC), 2011 IEEE International; 03/2011
-
[show abstract]
[hide abstract]
ABSTRACT: Thin-film transistors (TFTs) are a key element of flexible electronics implemented on low-cost substrates. Most TFT technologies, however, have only monotype-either n- or p-type-devices. In this paper, we propose a novel design style Pseudo-CMOS for flexible electronics that uses only monotype single-V<sub>T</sub> TFTs but has comparable performance with the complementary-type or dual-V<sub>T</sub> designs. The manufacturing cost and complexity can therefore be significantly reduced, whereas the circuit yield and reliability are enhanced with built-in postfabrication tunability. Digital cells are fabricated in two different TFT technologies, i.e., p-type self-assembled-monolayer-organic TFTs and n-type metal-oxide InGaZnO TFTs, to validate the proposed Pseudo-CMOS design style. To the best of our knowledge, this is the first design solution that has been experimentally proven to achieve superior performance for both types of TFT technologies.
IEEE Transactions on Electron Devices 02/2011; · 2.32 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We have successfully manufactured rubber-like large-area stretchable integrated circuits comprising printed elastic conductors and organic active components including transistors, and developed two applications; One is stretchable active matrix organic light-emitting diodes displays and the other is stretchable electromagnetic interference (EMI) measurement sheet that can detect EMI distribution on the surface of electronic devices by wrapping the devices in the sheet. The stretchable devices can spread over arbitrary surfaces including free-formed curvatures and movable parts, thereby significantly increasing the applications of electrical circuits.
Solid-State and Integrated Circuit Technology (ICSICT), 2010 10th IEEE International Conference on; 12/2010
-
[show abstract]
[hide abstract]
ABSTRACT: We have successfully fabricated a large-area flexible ultrasonic imaging system by integrating a polymeric ultrasonic-transducer array sheet with an active matrix of organic field-effect transistors. The ultrasonic sheet comprises 8 x 8 ultrasonic sensing cells with an effective size of 25 à 25 cm<sup>2</sup>. The organic transistors exhibit mobility of 0.1 and 0.5 cm<sup>2</sup>/V ·s at the low operation voltage of 1 mV and in the saturation regime, respectively. When an ac signal is applied between source and drain electrodes for the transistors with a grounded gate, the on/off ratio is larger than 10<sup>4</sup> at the carrier frequency of 40 kHz. In the linear sensing array comprising eight ultrasonic cells, crosstalk is suppressed sufficiently low, and the on/off ratio exceeds 10<sup>4</sup>. Images in free space are obtained for multiple-target objects over this sheet.
IEEE Transactions on Electron Devices 06/2010; · 2.32 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A stretchable 12 ?? 12 cm<sup>2</sup> electromagnetic interference (EMI) measurement sheet is developed to enable the measurement of EMI distribution on the surface of electronic devices by wrapping the devices in the sheet. The sheet consists of an 8 ?? 8 coil array, a 2 V organic CMOS row decoder and a column selector, 40% stretchable interconnects with carbon nanotubes, and 0.18 μm silicon CMOS circuits for electric and magnetic field detection. The sheet detects the total power of an electric field in the band up to 700 MHz and that of a magnetic field up to 1 GHz. The minimum detectable powers of the electric and magnetic fields are -60 and -70 dBm, respectively.
IEEE Journal of Solid-State Circuits 02/2010; · 3.23 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In the forthcoming ambient electronics era, multiple electronic objects are scattered on walls, ceilings or in imaginative locations and interact each other to enhance safety, security and convenience. For implementation of many electronic objects in our daily life, large-area, flexible devices, which would be printed on plastic sheet, cloth, and/or paper, are expected to play an important role. In this paper, we describe recent progress and future prospects of flexible, large-area electronics based on printed organic transistors.
Electron Devices Meeting (IEDM), 2009 IEEE International; 01/2010
-
[show abstract]
[hide abstract]
ABSTRACT: A novel communication system which simultaneously achieves the mobility of wireless communication and the low-power performance of wireline communication is developed with a printable sheet. By combining meter-scale wireline communication and micrometer-scale wireless capacitive-coupling communication, the proposed communication system enables multiple electronic objects scattered over tables, walls, and ceilings to communicate contactlessly with each other by establishing communication paths without cumbersome physical connections. The transceiver developed for the 20 cm times 20 cm communication sheet features a data-edge-signaling transmitter and a DC power-free pulse detector, thereby achieving the lowest energy of 107 pJ/bit at 100 kb/s in wireless communications at a distance of 60 cm in 0.18-mum CMOS.
Circuits and Systems I: Regular Papers, IEEE Transactions on 12/2009; · 1.97 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A flexible 12 cm times 12 cm EMI measurement sheet is developed to enable the measurement of the EMI distribution on the surface of the electronic devices by wrapping the devices in the sheet. The sheet includes 8times8 antenna array, 2V organic CMOS decoder, stretchable interconnects, and EMI detection LSI's (large scale integrations) in 0.18 mum CMOS. The distributed LSI's near the antennas enable the in-situ EMI measurement and have a potential to improve the measurement speed and accuracy. By changing the connection of the antenna to the LSI, the electric and magnetic fields are successfully measured separately. The minimum detectable magnetic field noise power was -70 dBm and the maximum detectable noise frequency was 1GHz. The minimum detectable electric field noise power was -60 dBm and the maximum detectable noise frequency was 700 MHz.
Electromagnetic Compatibility, 2009. EMC 2009. IEEE International Symposium on; 09/2009
-
[show abstract]
[hide abstract]
ABSTRACT: By using state-of-the-art printing technologies and functional inks, we have demonstrated organic nonvolatile flexible random-access-memory matrices with a nondestructive read-out capability and a time-continuous current output; these functionalities have not been simultaneously achieved even by silicon-based conventional memory. A memory cell comprising three transistors becomes possible with inkjet printing and other solution-based processes, which can use ferroelectric copolymer ink comprising poly(vinylidenefluoride-co-trifluoroethylene) and insulating ink comprising polyimide precursors properly within the planer plastic substrate. A large ldquo1 : 0rdquo current ratio of 10<sup>5</sup> is observed in air when it is annealed at 135degC , which is sufficiently low to be compatible with many plastic substrates. When stored in air, the ldquo1 : 0rdquo ratio was still 10<sup>4</sup> after 15 days and 10<sup>3</sup> after 5 months, which is sufficient for practical applications. Furthermore, human-scale communication sheets were manufactured as the first demonstration utilizing large-area organic memories.
IEEE Transactions on Electron Devices 06/2009; · 2.32 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We have successfully fabricated a large-area, flexible, ultrasonic system by integrating a two-dimensional polymeric ultrasonic sensing array with a printed organic transistor active matrix. The new sheet-type device can offer a cost-effective solution for a real-time three-dimensional imaging in free space and/or a large-area proximity sensor for robot skins.
Electron Devices Meeting, 2008. IEDM 2008. IEEE International; 01/2009
-
[show abstract]
[hide abstract]
ABSTRACT: Low-power wireless communications between electronic objects scattered over tables, walls and ceiling will form an infrastructure necessary for wireless sensor networks and ambient intelligence. A data edge-signaling scheme and DC power-free pulse detector allow the realization of a low energy/bit transceiver for use in a communication sheet, which allows the creation of infrastructure for ambient electronics when used together with the wireless power transmission sheet.
Solid-State Circuits Conference, 2008. ISSCC 2008. Digest of Technical Papers. IEEE International; 03/2008
-
[show abstract]
[hide abstract]
ABSTRACT: Human-scale communication sheets have been manufactured using printing processes with integrating an organic nonvolatile FeRAM with nondestructive read capability and plastic MEMS switches. The communication route is dynamically formed by MEMS switches and stored by the memory. The "1"-"0" ratio of the memory exceeds 10<sup>3</sup> after 10<sup>4</sup> cycles in air.
Electron Devices Meeting, 2007. IEDM 2007. IEEE International; 01/2008
-
[show abstract]
[hide abstract]
ABSTRACT: Design innovations that solve shortcomings of a wireless power transmission sheet are presented. The sheet is made with plastic MEMS switches and organic FET circuits. By using a level shifter with adaptive biasing in the organic circuit, the sheet can be directly driven using 5V digital input. It delivers power to multiple objects, frees the user from position adjustment, and reduces the number of coil arrays
Solid-State Circuits Conference, 2007. ISSCC 2007. Digest of Technical Papers. IEEE International; 03/2007
-
[show abstract]
[hide abstract]
ABSTRACT: An integrated system of organic FETs (OFETs) and plastic actuators is proposed, and it is applied to a Braille sheet display. Some circuit technologies are presented to enhance the speed and the lifetime for the Braille sheet display. An OFET SRAM is developed to hide the slow transition of the actuators. Developed five-transistor SRAM cell reduces the number of the bit lines by one-half and reduces the SRAM cell area by 20%. Pipelining the write-operation reduced the SRAM write-time by 69%. Threshold voltage control technology using a back gate increased the static noise margin of SRAM and compensated for the chemical degradation of the OFETs after 15 days. The oscillation frequency tuning range from -82% to +13% in a five-stage ring oscillator is also demonstrated with the threshold voltage control technology. The overdrive techniques for the driver OFETs reduced the transition time of the actuator from 34 s to 2 s. These developed circuit technologies achieved the practical 1.75-s operation to change all 144 Braille dots on Braille sheet display and will be essential for the future large area electronics made with OFETs
IEEE Journal of Solid-State Circuits 02/2007; · 3.23 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We have successfully manufactured a large-area power transmission sheet by using printing technologies. The position of electronic objects on this sheet can be contactlessly sensed by electromagnetic coupling using an organic transistor active matrix. Power is selectively fed to the objects by an electromagnetic field using a plastic MEMS-switching matrix
Electron Devices Meeting, 2006. IEDM '06. International; 01/2007
-
[show abstract]
[hide abstract]
ABSTRACT: This paper describes a sheet-type scanner and its circuits. The three-dimensional-stacked sheets comprise of two organic-transistor sheets and one organic-photodiode sheet, which enable double-wordline and double-bitline structure. The operation was compared with the conventional single-wordline and single-bitline scheme, and confirmed by measurement. The double-wordline and double-bitline structure reduces the line delay and power by a factor of five and seven, respectively. A new dynamic decoder reduces active leakage current, to which the cut-and-paste customization can be applied
IEEE Sensors Journal 11/2006; · 1.52 Impact Factor
-
Device Research Conference, 2006 64th; 07/2006
-
[show abstract]
[hide abstract]
ABSTRACT: Organic FETs (OFETs) are integrated with actuators and a Braille sheet display is demonstrated. A back-gated OFET SRAM and the circuit technology for the Braille sheet display to enhance speed, yield and lifetime are presented along with essential elements for future large-area electronics made with OFETs
Solid-State Circuits Conference, 2006. ISSCC 2006. Digest of Technical Papers. IEEE International; 03/2006
-
[show abstract]
[hide abstract]
ABSTRACT: We report the recent progress and future prospects of organic field-effect transistors and their applications to flexible, large-area sensors and actuators such as pocket image scanners for mobile applications, stretchable electronic artificial skins (E-skins) for robots, and Braille sheet display with plastic actuator arrays
Electron Devices Meeting, 2005. IEDM Technical Digest. IEEE International; 01/2006
-
Y. Kato,
S. Iba, T. Sekitani,
Y. Noguchi,
K. Hizu,
Xizhang Wang,
K. Takenoshita,
Y. Takamatsu,
S. Nakano,
K. Fukuda,
K. Nakamura,
T. Yamaue,
M. Doi,
K. Asaka,
H. Kawaguchi,
M. Takamiya,
T. Sakurai,
T. Someya
[show abstract]
[hide abstract]
ABSTRACT: A flexible, shock-resistant, and lightweight Braille sheet display has been successfully manufactured on a plastic film by integrating a plastic sheet actuator array with a high-quality organic transistor active matrix. This is the first demonstration, to the best of our knowledge, to integrate plastic MEMS (microelectromechanical systems) actuators with organic transistor active matrices, which opens up new versatile possibilities for flexible, large-area electronic applications including tactile displays
Electron Devices Meeting, 2005. IEDM Technical Digest. IEEE International; 01/2006
