A portable capacitive sensor was designed to assess frying oil degradation by measuring the changes in electrical capacitance. An interdigital electrode (IDE) was designed to be implemented as the testing probe (as IDEs are resistive to parasitic capacitance), together with an adjacent capacitive chip Pcap01 and a further microprocessor STM32, which were used as the data-processing elements. Experimental results demonstrated that viscosity could be a useful frying oil quality indicator, and also proved a preliminary correlation between IDE capacitance and oils’ total polar materials. This implies that IDE capacitance could be a suitable metric for conveniently assessing frying oil degradation. The designed capacitance sensor is light in weight, cost effective, and has excellent potential for simple, inexpensive, on-the-spot testing of the current quality of frying oil.

In this paper, thermally-stable, biocompatible and flexible luminescent films with self-healing capability were prepared by combining graphene quantum dots (GQDs) and silk fibroin (SF). Two methods were carried out to combine GQDs and SF: one is to feed silkworms with a GQDs diet and collect their cocoons; the other is to mix GQDs with SF solution directly. Then feeding GQDs/SF composite film and GQDs/SF mixing films of different mass ratios were prepared by natural air drying. The morphology, structure and performance of the SF films were characterized in detail. Results showed that the mixing composite films are flexible, luminescent and thermally stable. The more GQDs in the film, the stronger the luminescence is, in our case. The mixing films exhibit different light color under different excitations, the same with GQDs. However, fed GQDs in the silkworm seem to be playing a quenching effect on SF. It also showed that no new chemical bonds were formed between GQDs and SF, and the two were physically mixed, either by feeding or direct solution mixing. In addition, this fluorescent film also has the particular ability of self-healing by a drop of water. This new biocompatible film may have broad applications in fields of flexible display, biosensing, drug delivery and tissue engineering.

A transparent, conductive, smooth, and temperature sensitive thin films was fabricated and characterized in this paper. Silk fibroin could be processed into transparent thin films, which can act as ideal opto-electronic substrates. As pure silk fibroin film is nonconductive, ultra-long silver nanowires coating and platinum sputtering were used to strengthen its conductivity. Ultra-long nanowires were used to reduce the junctions between wires, and platinum was to improve the conductivity of the film. The new nanowire-metal-organic composite film possesses excellent conductivity and good transmittance. The composite films containing different silver nanowires exhibit conductivities of as low as 6.9 X/sq, and transmittance of 60-80% in the visible light range. The films also showed potentials in practical applications as their resistance is almost linearly temperaturedependent. It also can transfer power to electrical devices. The new composite films could be expected to function in wearable electronics or implantable devices and sensors.

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Micro/nano-manipulation is the fabrication of particular constructs on devices at the micro/nano-scale. Precise manipulation of microparticles is one of the key technological difficulties in manufacturing micro/nano-scale components. Based on scanning electron microscopy and nanomanipulator, this paper adopts a direct push method to operate randomly distributed microparticles into ordered structures. A two-probe interaction strategy is proposed to enable microparticle movements in all directions efficiently and avoid scratching the substrate surface. To overcome the uncertainties in micromanipulation, a virtual nano-hand strategy was also implemented: long-range advance of each microparticle is realized by multiple single-step pushes, whose trajectory is theoretically analyzed. The pushes are well programmed to imitate effects of a more powerful and determined hand. Experimental results show that the theoretical single-step motion trajectory is in line with actual operation, and the proposed strategy can ensure precise operation of the microparticles in all directions and improve reliability and effectiveness of operation.