Abstract: There is described a method of recovering parts of an electronic circuit having a self-supporting substrate having graphene oxide (GO) paper, and at least a conductive trace on the self-supporting substrate. The method generally has a step of immersing the electronic circuit into an environment-friendly solvent, the GO paper thereby dissociating from the conductive trace; and a step of recovering the GO paper from the environment-friendly solvent. The present disclosure also describes an electronic circuit generally having a self-supporting substrate having GO paper with a structural thickness being equal or above a given thickness threshold; and at least a conductive trace on said self-supporting substrate. Further, there is also described a substrate for an electronic circuit in which the substrate generally has a self-supporting substrate having GO paper with a structural thickness being equal or above a given thickness threshold.

Abstract: There is described a sensor for sensing a variable of a sample. The sensor generally has a graphene layer supported by a substrate; a parylene layer coating the graphene layer opposite the substrate; a sensing layer coating the parylene layer opposite the substrate, and being exposable to the sample; and electrical contacts at opposite ends of the graphene layer.

Abstract: The method can include depositing a graphene oxide containing material from solution to form a laminar nano-structure of graphene oxide paper, and assembling at least a portion of the graphene oxide paper as a diaphragm of the acoustic transducer. The acoustic transducer can be a magnetic induction based microphone, a diaphragm loudspeaker, or a magnetic induction based loudspeaker, for instance.

Abstract: Semiconductor light emitting diodes (LEDs) formed as (Al)GaN-based nanowire structures have a first semiconductor layer, a second semiconductor layer, and a thin metallic layer fabricated therebetween. The structures, operating in the deep ultraviolet (UV) spectral range, exhibit high photoluminescence efficiency at room temperature. The structures may be formed of an epitaxial metal tunnel junction operating as a reflector that enhances carrier transport to and from the semiconductor alloy layers, capable of producing external quantum efficiencies at least one order of magnitude higher than convention devices.

Abstract: There is described a sensor for sensing a variable of a sample. The sensor generally has a graphene layer supported by a substrate; a parylene layer coating the graphene layer opposite the substrate; a sensing layer coating the parylene layer opposite the substrate, and being exposable to the sample; and electrical contacts at opposite ends of the graphene layer.

Abstract: Semiconductor light emitting diodes (LEDs) formed as (Al)GaN-based nanowire structures have a first semiconductor layer, a second semiconductor layer, and a thin metallic layer fabricated therebetween. The structures, operating in the deep ultraviolet (UV) spectral range, exhibit high photoluminescence efficiency at room temperature. The structures may be formed of an epitaxial metal tunnel junction operating as a reflector that enhances carrier transport to and from the semiconductor alloy layers, capable of producing external quantum efficiencies at least one order of magnitude higher than convention devices.

Abstract: Materials used in acoustic transducer membranes need very specific qualities that in any real system require many tradeoffs to be made. Graphene and graphene related materials are a newly discovered class of materials with some exceptional properties that offer the potential for significant contributions to the performance of many acoustical transduction systems. Accordingly the inventors have established graphene oxide based transducers as the basis of ribbon microphones and diaphragm loudspeakers using low cost manufacturing and processing techniques.

Abstract: Cryogenic electronics based upon semiconductive devices, superconductive devices, or a combination of the two present opportunities for a wide variety of novel, fast, and low power devices. However, such cryogenic electronics require cooling which is typically achieved through fluid refrigerants such as liquid nitrogen or liquid helium. Solid state refrigeration based upon adiabatic demagnetization in paramagnetic salts offers one alternative but requires that the solid state cooler and cryogenic electronic circuits be different physical elements. The inventors present solid state cooling for semiconductor materials including but not limited to silicon. Beneficially active electronic devices can be integrated monolithically with solid state semiconductor coolers exhibiting magnetic cooling within the whole substrate or predetermined regions of the substrate. Alternatively, active devices may be formed with semiconductor layers integral to them that exhibit magnetic cooling.

Abstract: Cryogenic electronics based upon semiconductive devices, superconductive devices, or a combination of the two present opportunities for a wide variety of novel, fast, and low power devices. However, such cryogenic electronics require cooling which is typically achieved through fluid refrigerants such as liquid nitrogen or liquid helium. Solid state refrigeration based upon adiabatic demagnetization in paramagnetic salts offers one alternative but requires that the solid state cooler and cryogenic electronic circuits be different physical elements. The inventors present solid state cooling for semiconductor materials including but not limited to silicon. Beneficially active electronic devices can be integrated monolithically with solid state semiconductor coolers exhibiting magnetic cooling within the whole substrate or predetermined regions of the substrate. Alternatively, active devices may be formed with semiconductor layers integral to them that exhibit magnetic cooling.

Abstract: A novel multimode fiber structure with modal propagation characteristics tailored to facilitate the creation of narrowband, high reflectivity, fiber Bragg gratings is disclosed. The fiber structure comprises concentric cylindrical shells of higher and lower refractive index material. A full vector, second order finite element method is used to analyze the proposed multimode fiber structure. Simulations of the modal profiles show that high order modes are localized to particular high refractive index shells. We present the theoretical characterization of the modal propagation constant as a function of inner shell radius, shell separation, and harmonic mode parameter. It is shown that a fiber with a minimum inner shell radius of at least 25&lgr; (where &lgr; is the vacuum wavelength), and a minimum shell separation of at least 10&lgr; provides a reasonable trade off between fiber size and grating performance.

Abstract: A novel multimode fiber structure with modal propagation characteristics tailored to facilitate the creation of narrowband, high reflectivity, fiber Bragg gratings is disclosed. The fiber structure comprises concentric cylindrical shells of higher and lower refractive index material. A full vector, second order finite element method is used to analyze the proposed multimode fiber structure. Simulations of the modal profiles show that high order modes are localized to particular high refractive index shells. We present the theoretical characterization of the modal propagation constant as a function of inner shell radius, shell separation, and harmonic mode parameter. It is shown that a fiber with a minimum inner shell radius of at least 25&lgr; (where &lgr; is the vacuum wavelength), and a minimum shell separation of at least 10&lgr; provides a reasonable trade off between fiber size and grating performance.