Isotactic polypropylenes (iPP) with different melt flow indexes were melt blended with cellulose acetate butyrate (CAB) and then prepared into microspheres or nanofibers following a novel process of producing well dispersed CAB/iPP immiscible blends and subsequent removal of the CAB matrix. The morphologies of iPP microspheres were investigated by a scanning electron microscopy, and the dimensions of iPP microspheres were evaluated. The melt viscosities of iPP, CAB, and CAB/iPP blends were measured by using a capillary rheometer. The influences of the viscosity, viscosity ratio, and composition ratio of iPP/CAB on the morphology formation of iPP in CAB matrix were studied.

Poly(ethylene-co-acrylic acid) (PE-co-AA) fibers in sizes of 200-500 nm were prepared by using a novel melt-extrusion-extraction fabrication process. The thermoplastic nanofibers could be controllably dispersed and reassembled by a novel solvent exchange filtration method. The dispersed PE-co-AA nanofibers possess active surface areas and could directly conduct chemical reactions on surfaces. Surface modifications and organic synthesis on the nanofibers were proven effective and controllable after the dispersion. Multistep synthesis of biomolecules, such as peptide ligand HWRGWV against Fc portion of human IgG, was successful. The surface-anchored ligand has shown bioactivity through selective binding to and staining by human IgG-alkaline phosphatase conjugate. Another peptide, LXY3, a selective cyclic peptide ligand against alpha3beta1 integrin of MDA-MB-231 breast cancer cells, was also prepared on the surfaces of the dispersed nanofibers. The results showed that MDA-MB-231 cells were able to specifically bind to and grow on surfaces of the nanofibers that were functionalized with LXY3.

Immiscible blends of cellulose acetate butyrate (CAB) and poly(trimethylene terephthalate) (PTT) were melt extruded through a two strand rod die. The extrudates were hot-drawn at the die exit at different draw ratios. PTT fibers were obtained by removal of the CAB matrix from the drawn extrudates, and the morphology evolution of the formed fibers was investigated by scanning electron microscopy. PTT nanofibers with an average diameter of 55nm were produced by controlling the drawing ratio.

Immiscible blends of cellulose acetate butyrate (CAB) and isotactic polypropylenes (iPPs) with different melting index were extruded through a two-strand rod die. The extrudates were hot-drawn at the die exit at different draw ratios by controlling the drawing speed. The morphologies of iPP fibers extracted from the as-obtained extrudates after removal of CAB by acetone were investigated by scanning electron microscopy. The influences of draw ratio, viscosity ratio, and composition ratio of CAB/iPP on the morphology evolution of iPP phase into nanofibers in the immiscible blends were studied. It was found that the thermoplastic iPP nanofibers were formed from the elongation of iPP ellipsoids, end-to-end merging of elongated iPP microfibers, and the size decrease of iPP microfibers in the processes of extrusion and drawing. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 921-931, 2010

The composites of carbon black-filled silicon rubber are obtained aimed the usage in field of robotic sensor because of its conductivity and flexibility.The effects of the nano-silica and nano-alumina on the dispersion of carbon black in silicon rubber were analyzed with Scanning Electronic Microscopy(SEM). The conductivity and piezoresistance character were measured and the effects of nano particles were investigated.The results indicate that the nano particles have the effect of dispersion and erosion,and on optimum percentage,conductive rubber with better conductivity and linear piezoresistance was achieved.

Based on the use of piezoresistive effect of a 3×3 matrix of flexible tactile sensor,a new signal processing circuit is designed.The circuit can fulfill requirement as follows:signal amplification,choosing signal from sensor array,A/D conversion and collecting signal by LED circuit.And the principle and the circuit chip with the function are detailed.The signal processing circuit designed can determine which suffered three-dimensional tactile sensor unit load size and position of power.Through the loading experiment at positive pressure,the feasibility of the circuit is verified.

Surfaces of polypropylene (PP) fabrics were modified through thermal initiated radical graft polymerization with acrylic acid and poly (ethylene glycol) di-acrylate (PEG-DIA). Various polymerization conditions were studied to determine the optimal parameters leading to the best surface functionality. Carboxylic acid groups on the functionalized PP support were further derivatized for solid phase peptide synthesis. Peptide ligands LHPQF and sppLDI were successfully synthesized through simple coupling reactions utilizing Fmoc chemistry. Specific binding of Streptavidin–Alkaline phosphatase conjugate and Jurkat (T lymphoblastic) cell were successfully achieved on the novel functional PP substrates. The good geometrical flexibility, mechanical stability, chemical reactivity and biocompatibility of this novel planar support make it very promising substrate for various biotechnological applications.

In this paper,a bandgap voltage reference with high PSRR and low noise is proposed.The circuit is designed using the 0.6 μm N well CMOS process.Based on the conventional bandgap reference circuit,a simple voltage subtractor circuit is incorporated.The subtractor feeds the supply noise directly into the feedback loop of the bandgap circuit which can help to suppress supply noise and improve the PSRR.The Cadence Spectre simulation result shows that the proposed bandgap voltage reference has a temperature coefficient of 26×10-6/℃ between-25 ℃ and 85 ℃ and the RMS noise of 43 μV from 10 Hz to 100 kHz,and its PSRR gets to 110 dB at the low frequencies.

To obtain conductive rubber with favorable pressure-resistance and resistance-temperature properties,and to meet with the demands of robots complex sensors research,the conductive silicone rubber doped with different concentration of nano SiO2 and Al2O3 particles respectively,and conductive particles carbon black were compounded.The characteristics of pressure-resistance,resistance-temperature,stability,and sensitivity properties were measured.The results demonstrate that linear pressure-resistance,linear resistance-temperature can be obtained when the nano particles and conductive ones doped in proper scale,and meanwhile the stability and sensitivity can be improved.The linear is tic are due to the dispersion and enhance effects of the nano particle in the rubber matrix,while the improved sensitivity and stability characteristics are due to the enhance effects of them.The potential applications of this complex conductive silicone rubber in complex sensor were indicated.

Two Types of tactile sensor of robot that can measure three-dimension force based on pressure sensitive conductive rubber are proposed. The two effects of the body piezoresistive and the interface piezoresistive of pressure sensitive conductive rubber were researched and compared. A type of single-layer and a type of multi-layer net tactile sensor array of robot according to piezoresistive effects have been designed. We have herein obtained the mathematical models of calculating three dimension forces for two different array structures. The tactile sensor units were made and the change of output resistances of pressure sensitive conductive rubber of sensor array unit have been obtained under the action of three dimensional forces. The experimental results and applications for two tactile sensor arrays were analysed. Results show that the flexible tactile sensor for robot has a simple design, fine flexibility, and can measure the information of three-dimensional force.

This paper designs a new robot flexible tactile sensor that can measure three-dimension force based on flexible pressure-sensitive conductive rubber.It studies on the piezoresistive effect of pressure-sensitive conductive rubber,illustrates on the designing thoughts of tactile sensor,and researches on the tactile sensor's unit design and array structure respectively.It obtains the mathematical model of calculating three dimension forces,and gains the verification of three dimension force by experiments.The results indicate that the designed three-dimension force flexible tactile sensor for robot has the advantage of simple design,low costs and fine flexibility.Besides,it can be disposed in array to acquire the information of three-dimension force in medication,physics and robots.

New flexible sensitive materials research in the tactile sensor especially in the field of robot sensor has a very important role. From the perspective of macro and microscopic theory, this paper studies the conductive mechanism based on the pressure-sensitive conductive composite material of such flexible tactile sensor, through the experiment of adding conductive filled composite materials of different contents, determine the carbon black filler content of the pressure-sensitive conductive composite material in insulation zone, percolation zone and conductive zone. By utilizing the general effective media (GEM) and quantum tunnel effect theory, it explains the conductive characteristics and piezoresistive characteristics of the carbon black filled pressure-sensitive conductive composite material. It studies the influence of the temperature to conductive performance of the pressure-sensitive composite material according to the conductive mechanism of the pressure-sensitive conductive composite material, which provides theoretical foundation for researches of such new flexible tactile sensor material.

Poly(ethylene-co-glycidyl methacrylate) (PE-co-GMA) nanofibers with abundant active epoxy groups on surfaces were fabricated through a novel manufacturing process. The prepared PE-co-GMA nanofibers with different average diameters ranging from 100 to 400 nm were aminated by reacting the epoxy groups with 1,3-diaminopropane. The resulting aminated PE-co-GMA nanofibers were subsequently biotinylated and then successfully applied to immobilize streptavidin–horseradish peroxidase (HRP) conjugate via specific, strong and rapid binding of biotin and streptavidin. The streptavidin–HRP immobilized PE-co-GMA nanofibers showed high activity, efficiency, sensitivity as well as good reusability. The results demonstrated that PE-co-GMA nanofibers prepared could be a promising candidate as solid support materials for potential biosensor applications.

A method of measure the information of three-dimensional force tactile sensing based on flexible pressure sensitive conductive rubber has been presented. The conductive mechanism and piezoresistivity of flexible pressure sensitive conductive rubber ware analyzed. A new type three dimensional force net array structure of flexible tactile sensor of robot sensitive skin has been designed. The mechanics model of the three-dimensional force has been found. Through experimental study the three-dimensional force based on the tactile sensor units, the change output resistances of pressure sensitive conductive rubber of sensor array unit have been obtained under action of three dimensional forces. All which provided the effective basis for the confirmation experiment result and the new structural design. The results show that pressure-sensitive conductive rubber with fine electrical and mechanical properties for flexible tactile sensors. The robot sensitive skin using this material feels like the skin of human being and measure the information of multi-dimensional force.

The piezoresistive effect of pressure-sensitive conductive rubber was discussed and verified by experiment. The mathematical model of calculating three-dimension force is obtained. After that, the sensor array and the signal processing circuit were designed. By means of experiments, the verification of three-dimension force was given and the results were analyzed. The results showed that the new design of three-dimension force tactile sensor is accord with the design requirements, which provided a new idea for the further research of flexible three-dimension force sensor.

Resistance temperature characteristic of pressure sensitive conductive silicone rubber is discussed based on flexible tactile sensor from conductive mechanism.Analyses are made on the methods of improving temperature stability of pressure sensitive conductive silicone rubber on the basis of experiments.The results show that increased the carbon black content of pressure sensitive conductive silicone rubber within the scope to meet the requirements of the tactile sensor design and mixed with nanomaterials can effectively improve the resistance temperature characteristic of the pressure sensitive conductive silicone rubber.