Light-Assisted Enhancement of Gas Sensing Property for Micro-Nanostructure Electronic Device: A Mini Review

In recent years, gas sensing electronic devices have always attracted wide attention in the field of environment, industry, aviation and others. In order to improve the gas sensing properties, many micro- and nano-fabrication technologies have been proposed and investigated to develop high-performance gas sensing devices. It is worth noting that light irradiation is an effective strategy to enhance gas sensitivity, shorten the response and recovery time, reduce operating temperature. In this review, firstly, the latest research advances of gas sensors based on different micro-nanostructure materials under UV light and visible light activation is introduced. Then, the gas sensing mechanism of light-assisted gas sensor is discussed in detail. Finally, this review describes the present application of gas sensors with improved properties under light activation assisted conditions and the perspective of their applications.

Combination of Ceramic Laser Micromachining and Printed Technology as a Way for Rapid Prototyping Semiconductor Gas Sensors

The work describes a fast and flexible micro/nano fabrication and manufacturing method for ceramic Micro-electromechanical systems (MEMS)sensors. Rapid prototyping techniques are demonstrated for metal oxide sensor fabrication in the form of a complete MEMS device, which could be used as a compact miniaturized surface mount devices package. Ceramic MEMS were fabricated by the laser micromilling of already pre-sintered monolithic materials. It has been demonstrated that it is possible to deposit metallization and sensor films by thick-film and thin-film methods on the manufactured ceramic product. The results of functional tests of such manufactured sensors are presented, demonstrating their full suitability for gas sensing application and indicating that the obtained parameters are at a level comparable to those of industrial produced sensors. Results of design and optimization principles of applied methods for micro- and nanosystems are discussed with regard to future, wider application in semiconductor gas sensors prototyping.

Self-powered bifunctional sensor based on tribotronic planar graphene transistors

With the development of material science, micro-nano-fabrication and microelectronics, the higher level requirements are posed on the electronic skins (E-skin). The lower energy consumption and multiple functions are the imperative requirements to spurred scientists and mechanists to make joint efforts to meet. To achieve lower energy consumption, a promising energy-harvesting style of triboelectric nanogenerators (TENG) is incorporated into the field effect transistors (FETs) to play the important role for sensor. For bifunctional sensor, to harness the difficult for reflecting the magnitude of frequency, we resorted to synaptic transistors to achieve more intelligentization. Furthermore, with regards to the configuration of FET, we continued previous work: using the electrolyte gate dielectrics of FET—ion gel as the electrification layer to achieve high efficient, compact and extensively adoption for mechanosensation. The working principle of the GFET was based on the coupling effects of the FET and the TENG. This newly emerged self-powered sensor would offer a new platform for lower power consumption sensor for human–machine interface and intelligent robot.

Reliability Failure in Microelectronic Interconnects by Electric Current Induced Chemical Reaction

The electric field-induced chemical reaction in Cr thin film by a micro/nano-probe has been recently reported with detailed characterization. Although the phenomenon is employed for micro-nano fabrication, this can act as a reliability failure, where Cr is used as an adhesion layer or main interconnects in microelectronic circuits. Here, we present an investigation on the role of electric current density for such failure using a specifically designed sample. A 100 μm width and 100 nm thin Cr film is deposited perpendicular to the Pt film of similar dimensions. The anode probe (20 μm diameter) is positioned onto the Pt film, whereas the cathode probe onto the Cr film. It is observed that the chemical reaction, for an applied voltage, initiates at the edge of the Pt film and not at the cathode probe. The localized chemical reaction causes to damage the interconnection line. The analysis based on the COMSOL multiphysics simulation illustrates that the chemical reaction evolves at the high current density locations. The study also builds a fundamental understanding of the mechanism of evolution of patterning by electric field-induced chemical reactions.

Nanofabrication Techniques: Challenges and Future Prospects

Nanofabrication of functional micro/nano-features is becoming increasingly relevant in various electronic, photonic, energy, and biological devices globally. The development of these devices with special characteristics originates from the integration of low-cost and high-quality micro/nano-features into 3D-designs. Great progress has been achieved in recent years for the fabrication of micro/nanostructured based devices by using different imprinting techniques. The key problems are designing techniques/approaches with adequate resolution and consistency with specific materials. By considering optical device fabrication on the large-scale as a context, we discussed the considerations involved in product fabrication processes compatibility, the feature’s functionality, and capability of bottom-up and top-down processes. This review summarizes the recent developments in these areas with an emphasis on established techniques for the micro/nano-fabrication of 3-dimensional structured devices on large-scale. Moreover, numerous potential applications and innovative products based on the large-scale are also demonstrated. Finally, prospects, challenges, and future directions for device fabrication are addressed precisely.

Simple Fabrication of Solid-State Nanopores on a Carbon Film

Solid-state nanopores are widely used as a platform for stochastic nanopore sensing because they can provide better robustness, controllable pore size, and higher integrability than biological nanopores. However, the fabrication procedures, including thin film preparation and nanopore formation, require advanced micro-and nano-fabrication techniques. Here, we describe the simple fabrication of solid-state nanopores in a commercially available material: a flat thin carbon film-coated micro-grid for a transmission electron microscope (TEM). We attempted two general methods for nanopore fabrication in the carbon film. The first method was a scanning TEM (STEM) electron beam method. Nanopores were fabricated by irradiating a focused electron beam on the carbon membrane on micro-grids, resulting in the production of nanopores with pore diameters ranging from 2 to 135 nm. The second attempt was a dielectric breakdown method. In this method, nanopores were fabricated by applying a transmembrane voltage of 10 or 30 V through the carbon film on micro-grids. As a result, nanopores with pore diameters ranging from 3.7 to 1345 nm were obtained. Since these nanopores were successfully fabricated in the commercially available carbon thin film using readily available devices, we believe that these solid-state nanopores offer great utility in the field of nanopore research.

Self-powered Bifunctional Sensor Based on Tribotronic Planar Graphene Transistors

With the development of material science, micro-nano-fabrication, microelectronics, the higher level requirements are posed on the electronic skins (E-skin). The lower energy consumption and multiple functions are the imperative requirements to spurred scientists and mechanists to make joint effort to meet. To achieve lower energy consumption, a promising energy-harvesting style of triboelectric nanogenerators (TENG) is incorporated into the field effect transistors (FETs) to play the important role for sensor. For bifunctional sensor, to harness the difficult for reflecting the magnitude of frequency, we resorted to synaptic transistors to achieve more intelligentization. Furthermore, with regards to the configuration of FET, we continued previous work: using the electrolyte gate dielectrics of FET - ion gel as the electrification layer to achieve high efficient, compact and extensively adoption for mechanosensation. The working principle of the GFET was based on the coupling effects of the FET and the TENG. This novel self-powered sensor would offer a new platform for lower power consumption sensor for human-machine interface and intelligent robot.