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This article reports on the design, fabrication, and characterization of an in-pipe worm-like soft robot with pneumatic actuators based on origami paper-fabric composites in which the paper and fabric serve as the skeleton and skin of the robot, respectively. The robot is assembled with an extensor of a bellow-like structure for implementing peristaltic locomotion and a clamp fabricated using a Kresling crease pattern at each end of the robot for anchoring. The performances of the pneumatic actuators, as well as the worm robot, are characterized and their dependence on some material, structural, and pneumatic parameters are investigated. Stepwise inflation of the clamp actuator takes place as the pressurization duration increases. The extension ratio of the extensor has a nonlinear relationship with the pressurization duration. The higher rigidity of the paper with a high weight per unit area can facilitate faster retention near the end of the extension process for the extensor with a small number of creases, while it becomes a resistance for the extension of the extensor with a large number of creases. The softness, lightweight features, low cost, ease to fabricate, modular design, and mobility of the worm robot indicate it has potential to find application in pipeline inspection, etc. [ABSTRACT FROM AUTHOR]

A kind of paper-based composite was prepared with short carbon fibers (CFs) and para-aramid fibrids through the process of papermaking. The dielectric properties of the paper-based composites at microwave frequency were investigated. Based on the Lichtenecker Rule, the dielectric constants of CFs in composites at different CF concentrations were calculated. The absorbing performances of paper-based composites were calculated from the test results of electromagnetic parameters. It was shown that for the composites loaded with 1 mm CFs, the real part of complex permittivity rises at first then tends to be stable with the increase of the CF content, and the imaginary part rises at first then falls slightly, while for composites loaded with 3 or 6 mm CFs, both the real and imaginary part of complex permittivity grows at first and then falls rapidly with the CF content increasing. When the CF content is below 10 wt%, the composites containing longer CFs have larger permittivity at the same concentration. The Lichtenecker Rule is found to be not suitable for the system studied in this paper, especially when the content of CFs is high. The variations of reflectance and absorbance with the content of CFs generally have analogous trends . It is also found that to achieve better absorbing performance, the length and content of CFs together with the thickness of composites should be considered. In this study, the lowest reflection loss at 10 GHz reaches –27.59 dB when the paper-based composite is loaded with 1 mm CFs at the concentration of 10 wt% and the optimum thickness of 1.84 mm. [ABSTRACT FROM AUTHOR]

The manipulation of the physical characteristics of nonwovens and paper by variation of fiber and web geometry is briefly reviewed in terms of a new system of bonding in which the adhesive interfiber forces are a consequence of ionic chemical bonds.These bonds were created by the sequential covalent introduction of anionic sites onto the interior and exterior surfaces of microporous pulp and rayon fibers using a chloro-s-triazinyl fiber reactive dye and subsequent stoichiometric reaction with crosslinking polycations derived from ethylenimine.The tensile properties of both the pulp and rayon fiber assemblages were significantly augmented as a result of the development of both ionic inter- and intra-fiber bonds. [ABSTRACT FROM PUBLISHER]

The biodegradability of several packaging films was determined; the degradation of the polymeric films, polypropylene and poly(vinyl chloride), was compared to a coated paper and several coated cellophanes. The films were buried in bacterially-active soil and the extent of bacterial degradation was determined by measuring the reduction in tensile strength as a function of burial time. The results show that the polymeric films do not degrade after five weeks of soil burial while the glassine and cellophanes do degrade. Surprisingly, the cellophane films decompose at a faster rate than the coated glassine sheet. [ABSTRACT FROM PUBLISHER]