Abstract: A chemical process to formulate conductive ink with low sintering temperature for inkjet printing is described and shown. The application of fabricated flexible conductive film on lithium ion batteries is also described. This chemical method and composition can remove the oxidation on metallic nanoparticle surface during ink fabrication and sintering processes. Etched metallic ions in the conductive ink are reduced and particles bridged while annealing printed patterns to achieve low temperature sintering at about 350° C. The chemical process can be applied on nickel materials that are excellent current collectors for lithium ion batteries due to high chemical stability especially at high charging-discharging potential of less than 3 Volts. Thermal decomposition and chemical reduction of silver salts are two methods disclosed for particle-free silver ink. Surfactant additive further make silver film more uniform and easier to be sintered.

Abstract: A chemical process to formulate conductive ink with low sintering temperature for inkjet printing is described and shown. The application of fabricated flexible conductive film on lithium ion batteries is also described. This chemical method and composition can remove the oxidation on metallic nanoparticle surface during ink fabrication and sintering processes. Etched metallic ions in the conductive ink are reduced and particles bridged while annealing printed patterns to achieve low temperature sintering at about 350° C. The chemical process can be applied on nickel materials that are excellent current collectors for lithium ion batteries due to high chemical stability especially at high charging-discharging potential of less than 3 Volts. Thermal decomposition and chemical reduction of silver salts are two methods disclosed for particle-free silver ink. Surfactant additive further make silver film more uniform and easier to be sintered.

Abstract: Flexible metamaterials and three-dimensional metamaterials operable in the terahertz range are disclosed. Methods are disclosed for fabricating terahertz response metamaterials using microfluidic-jetted techniques. Layers of material including substrate and deposited material are stacked to form three dimensional bulk metamaterials. The fabricated metamaterials act as left-handed metamaterials in the range 0.1 to 3.0 THz.

Abstract: An interferometric and synthetic aperture THz incoherent imaging system is provided, in which a high-power electronic source such as a 0.094 THz Gunn Oscillator is integrated with a continuous-wave (CW) terahertz detection system in order to achieve a high signal-to-noise ratio. THz imaging of a point source located 10 m away from the detector array is presented. A 2-D THz reflective image is reconstructed with only four detectors using rotational synthesis.

Abstract: Non-invasive THz spectroscopic apparatus and methods are provided for detecting and/or identifying constituents such as variations in a structural entity where chemical or biological entities can reside. Position dependent scattering of THz radiation is employed to image voids and defects in the internal structure of samples, enabling the determination of contamination, spoilage or readiness of products such as wine in sealed containers.

Abstract: An interferometric and synthetic aperture THz incoherent imaging system is provided, in which a high-power electronic source such as a 0.094 THz Gunn Oscillator is integrated with a continuous-wave (CW) terahertz detection system in order to achieve a high signal-to-noise ratio. THz imaging of a point source located 10 m away from the detector array is presented. A 2-D THz reflective image is reconstructed with only four detectors using rotational synthesis.

Abstract: Methods and apparatus are provided employing rapid scanning continuous wave terahertz spectroscopy and imaging for the non-destructive evaluation of materials such as animal hides and natural cork, and explosive detection, concealed weapon detection, and drug detection. A system employing an aperiodic detector array and implementing phase modulation at 100 kHz significantly reduces the imaging time and enables interferometric images of a THz point source to be obtained at several frequencies between 0.3 and 0.95 THz.

Abstract: Rapid, voltage controlled phase modulation of continuous wave THz radiation is demonstrated. By transmitting an infrared laser beam through a phase modulator, the phase of the THz radiation which is generated by the photomixing of two infrared beams can be directly modulated through a 2? phase shift. The 100 kHz modulation rate that is demonstrated is approximately three orders of magnitude faster than what can be achieved by mechanical scanning.

Abstract: Non-invasive THz spectroscopic apparatus and methods are provided for detecting and/or identifying constituents such as variations in a structural entity where chemical or biological entities can reside. Position dependent scattering of THz radiation is employed to image voids and defects in the internal structure of samples, enabling the determination of contamination, spoilage or readiness of products such as wine in sealed containers.

Abstract: Flexible metamaterials and three-dimensional metamaterials operable in the terahertz range are disclosed. Methods are disclosed for fabricating terahertz response metamaterials using microfluidic-jetted techniques. Layers of material including substrate and deposited material are stacked to form three dimensional bulk metamaterials. The fabricated metamaterials act as left-handed metamaterials in the range 0.1 to 3.0 THz.

Abstract: Ultra-miniaturized THz spectrometer/multi-channel receiver devices are provided. THz communication devices employ a THz transmitter, a THz receiver and a modulator, wherein the THz transmitter is configured to introduce a THz signal to the modulator and the THz receiver is configured to receive the THz signal from the modulator and demodulate the signal. Communication systems and methods employing the THz spectrometer/multi-channel receiver devices enable secure communications. Portable THz emitter devices are provided employing semiconductor lasers and a nonlinear birefringent waveguide monolithically integrated on the same substrate.

Abstract: Rapid, voltage controlled phase modulation of continuous wave THz radiation is demonstrated. By transmitting an infrared laser beam through a phase modulator, the phase of the THz radiation which is generated by the photomixing of two infrared beams can be directly modulated through a 2? phase shift. The 100 kHz modulation rate that is demonstrated is approximately three orders of magnitude faster than what can be achieved by mechanical scanning.

Abstract: Methods and apparatus are provided employing rapid scanning continuous wave terahertz spectroscopy and imaging for the non-destructive evaluation of materials such as animal hides and natural cork, and explosive detection, concealed weapon detection, and drug detection. A system employing an aperiodic detector array and implementing phase modulation at 100 kHz significantly reduces the imaging time and enables interferometric images of a THz point source to be obtained at several frequencies between 0.3 and 0.95 THz.

Abstract: Methods to infer the density of defects in high ? dielectric films in a non-contact, non-invasive and non-destructive manner. THz radiation is employed to measure the change in electrical conductivity of the films before and after illumination with visible light, where the visible light photoionizes the defects thereby changing the electrical conductivity and changing the transmission (or reflection) of THz radiation from the films. The disclosed techniques can be employed to make measurements as soon as wafers are fabricated. The technology is applicable to wafers of any size.