Publications by authors named "David McCoul"

In this article, a cable-driven elastic backbone worm-like robot (named "SpringWorm") of decimeter-level size is designed, which has high adaptability in crack inspection of the weld between reactor pressure vessel (RPV) and control rod drive mechanisms. The robot consists of a body that adopts a rectangular helix spring backbone driven by four cables and the flexible claws embedded with distributed electromagnets. Combining the omnidirectional deformation of the backbone and the passive deformation adsorption of the claws, the robot can achieve a variety of gaits.

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Some applications are very sensitive to the weight of the robot, such as space manipulation or any untethered mobile manipulation. In this article, we designed a five-module unilaterally bending serial manipulator with length of 32 cm and a weight of only 18 g. The manipulator is driven by dielectric elastomer actuators (DEAs).

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Existing robots capable of hopping or running mostly rely on rigid actuators, but soft hopping or running robots based on muscle-like actuators have not yet been achieved. In this article, we report a tethered soft robot capable of hopping-running on smooth and rough surfaces with high speed. The hopping-running robot is composed of two soft joints that simulate the foreleg and hind leg driven by dielectric elastomer.

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Hierarchical nanofibrous scaffolds are emerging as a promising bone repair material due to their high cell adhesion activity and nutrient permeability. However, the existing method for hierarchical nanofibrous scaffolds fabrication is complicated and not perfectly suitable for further biomedical application in view of both structure and function. In this study, we constructed a hierarchical nanofibrous poly (l-lactic acid)/poly(ε-caprolactone) (PLLA/PCL) scaffold and further evaluated its bone healing ability.

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Repairing large tumor-related bone defects remains a difficult clinical problem because of the significant risk of locoregional relapse after surgical curettage. In this study, a composite scaffold of nano-hydroxyapatite (nHA) and reduced graphene oxide (rGO) sheets was fabricated by self-assembly, and a 20 wt% nHA-rGO sheet solution formed the most stable hydrogel. , nHA-rGO scaffolds killed all but 8% of osteosarcoma cells (MG-63) under 808 nm near-infrared laser irradiation for 20 min.

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Hemostasis is of critical importance for damage control and the initiation of tissue repair in surgery and trauma. Mesoporous silica materials, due to their favorable biocompatibility and excellent surface properties, have attracted increasing attention for their outstanding hemostatic performance. In this study, silver nanoparticle-incorporated mesoporous silica granules (AgNP-MSG) were prepared by means of one-pot sol-gel processing, which brought about a highly blood-absorbent composite capable of prompt hemostasis.

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Motion capture of the human body potentially holds great significance for exoskeleton robots, human-computer interaction, sports analysis, rehabilitation research, and many other areas. Dielectric elastomer sensors (DESs) are excellent candidates for wearable human motion capture systems because of their intrinsic characteristics of softness, light weight, and compliance. In this paper, DESs were applied to measure all component motions of the wrist joints.

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This article describes the development of an analytical model to study the coupled nonlinear oscillation and stability evolution of viscoelastic dielectric elastomers (DEs) under non-equibiaxial tensile forces by utilizing the method of virtual work. Numerically calculated results are employed to predict this nonlinear dynamic behavior. The resonant frequency (where the amplitude-frequency response curve peaks) and the amplitude-frequency response of the deformation in both in-plane directions are tuned by varying the values of tensile force.

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