A herringbone soft pneu-net actuator for enhanced conformal gripping

Advances in material science in recent years have had such a tremendous impact on the field of soft robotics that has fostered the development of many bio-inspired devices. One such device, which has been subject to extensive study in recent times, is soft pneumatic-network (pneu-net) actuators (SPAs). In this study, we present a new SPA structure whose chamber configuration mimics the fish bone (herringbone) structure to facilitate simultaneous bending deformations in both longitudinal and transverse directions. Such as cannot be obtained from the regular pneu-net structure – which bends only lengthwise, the coupled bending curvatures allow for gripping with maximized contact area, a property which facilitates firmness, security, and stability in gripping. Using the corresponding chamber inclination angle of the configuration as key parameter, the combined transverse and longitudinal deformation feature is studied through finite element simulation as well as experiments. Also, the functional behavior of the actuator/gripper prototypes is experimentally investigated using a series of approaches including blocked (or tip) force test, grip strength test, and stability (or sustained grasping force) test. Furthermore, the viability of the said conformal gripping characteristic is demonstrated by subjecting the structure to a couple of gripping tests. This utility-enhancing design approach could really guide into the development of more sophisticated application-custom soft robotic capabilities.

Mobility anisotropy in the herringbone structure of asymmetric Ph-BTBT-10 in solution sheared thin film transistors

Thin films of the organic semiconductor Ph-BTBT-10 and blends of this material with polystyrene have been deposited by a solution shearing technique at low (1 mm/s) and high (10 mm/s)...

Integration of Hierarchical Micro-/Nanostructures in a Microfluidic Chip for Efficient and Selective Isolation of Rare Tumor Cells

Circulating tumor cells (CTCs) are important clinical markers for both cancer early diagnosis and prognosis. Various techniques have been developed in the past decade to isolate and quantify these cells from the blood while microfluidic technology attracts significant attention due to better controlled microenvironment. When combined with advanced nanotechnologies, CTC isolation performance in microfluidic devices can be further improved. In this article, by extending the wavy-herringbone concept developed earlier in our team, we prepared a hierarchical microfluidic chip by introducing a uniform coating of nanoparticles with anti-epithelial cell adhesion molecule (EpCAM) on wavy microgrooves. This hierarchical structured platform not only maintains the capture purity of the wavy-herringbone structure but improves the capture efficiency thanks to the larger surface area to volume ratio brought by nanoparticles. Our results demonstrated a capture efficiency of almost 100% at a low shear rate of 60/s. Even at a higher shear rate of 400/s, the hierarchical micro/nanostructures demonstrated an enhancement of up to ~3-fold for capture efficiency (i.e., 70%) and ~1.5-fold for capture purity (i.e., 68%), compared to wavy-herringbone structures without nanoparticle coating. With these promising results, this hierarchical structured platform represents a technological advancement for CTC isolation and cancer care.

Crystal structure of 2,2′-bipyrrole

The complete molecule of the title compound, C8H8N2, is generated by a crystallographic center of symmetry. In the crystal, short N—H...π [H...π = 2.499 (19) Å] interactions link the molecules into a herringbone structure.