Xudong Yu

Bio: Xudong Yu is an academic researcher from Nanyang Technological University. The author has contributed to research in topics: Composite laminates & Chemistry. The author has an hindex of 10, co-authored 24 publications receiving 309 citations. Previous affiliations of Xudong Yu include City University of Hong Kong & Beihang University.

High-throughput mapping of brain-wide activity in awake and drug-responsive vertebrates

Abstract: The reconstruction of neural activity across complete neural circuits, or brain activity mapping, has great potential in both fundamental and translational neuroscience research. Larval zebrafish, a vertebrate model, has recently been demonstrated to be amenable to whole brain activity mapping in behaving animals. Here we demonstrate a microfluidic array system (“Fish-Trap”) that enables high-throughput mapping of brain-wide activity in awake larval zebrafish. Unlike the commonly practiced larva-processing methods using a rigid gel or a capillary tube, which are laborious and time-consuming, the hydrodynamic design of our microfluidic chip allows automatic, gel-free, and anesthetic-free processing of tens of larvae for microscopic imaging with single-cell resolution. Notably, this system provides the capability to directly couple pharmaceutical stimuli with real-time recording of neural activity in a large number of animals, and the local and global effects of pharmacoactive drugs on the nervous system can be directly visualized and evaluated by analyzing drug-induced functional perturbation within or across different brain regions. Using this technology, we tested a set of neurotoxin peptides and obtained new insights into how to exploit neurotoxin derivatives as therapeutic agents. The novel and versatile “Fish-Trap” technology can be readily unitized to study other stimulus (optical, acoustic, or physical) associated functional brain circuits using similar experimental strategies.

Feature guided wave inspection of bond line defects between a stiffener and a composite plate

Abstract: Adhesive bonding is widely used in aerospace composite structures. A continuous well-cured bond can offer good joint strength and improved fatigue and impact resistance, and is therefore crucial to the performance of the entire structure. This paper explores the feasibility of using feature guided waves (FGW) for rapid screening of the bond line between a stiffener and a carbon fiber reinforced polymer (CFRP) composite panel. Such FGWs are capable of focusing the wave energy along the stiffener and the bond layer, with limited radiation to the adjacent plate. The Semi-Analytical Finite Element (SAFE) approach is employed to understand the modal properties of FGWs that exist in the structure, and criteria are suggested to choose proper mode-frequency combination that is sensitive to adhesive defects. A shear horizontal type FGW mode is identified to be well suited, as it is easy to excite, and propagates with little dispersion and relatively low attenuation, while it retains sufficient energy around the bond layer. Both 3D Finite Element (FE) simulations and experiments are performed to study the interaction of the selected FGW mode with defects in the adhesive bond, and the results show excellent agreement. The reflection behavior and the wave-defect resonance phenomenon are investigated, which demonstrate the capability of the FGW for the bond line inspection.

Numerical modeling of embedded solid waveguides using SAFE-PML approach using a commercially available finite element package

Abstract: Guided waves are attractive for long range inspections from a single generation position. However when the waveguide is embedded in another medium, the energy of the guided waves may leak into the surrounding material, causing significant reduction of the inspection distance. A number of analytical or numerical models were developed to understand the behavior of guided waves in embedded waveguides, among which one of the attractive methods was to combine the Semi-Analytical Finite Element (SAFE) method with Perfectly Matched Layer (PML). This paper presents a development to implement the SAFE-PML model in a commercially available Finite Element package. As no source code is required, the presented method will be attractive to a wide range of researchers in Non-Destructive Evaluation (NDE). The model is first demonstrated and validated in two cases with analytical solutions. Discussions have been carried out regarding the procedure to select proper modeling parameters. The potential of the model is also illustrated on an important application of guided waves along embedded pipelines.

Principles of Neural Science

Abstract: I have developed "tennis elbow" from lugging this book around the past four weeks, but it is worth the pain, the effort, and the aspirin. It is also worth the (relatively speaking) bargain price. Including appendixes, this book contains 894 pages of text. The entire panorama of the neural sciences is surveyed and examined, and it is comprehensive in its scope, from genomes to social behaviors. The editors explicitly state that the book is designed as "an introductory text for students of biology, behavior, and medicine," but it is hard to imagine any audience, interested in any fragment of neuroscience at any level of sophistication, that would not enjoy this book. The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or

Microfluidic Organ/Body-on-a-Chip Devices at the Convergence of Biology and Microengineering.

Abstract: Recent advances in biomedical technologies are mostly related to the convergence of biology with microengineering. For instance, microfluidic devices are now commonly found in most research centers, clinics and hospitals, contributing to more accurate studies and therapies as powerful tools for drug delivery, monitoring of specific analytes, and medical diagnostics. Most remarkably, integration of cellularized constructs within microengineered platforms has enabled the recapitulation of the physiological and pathological conditions of complex tissues and organs. The so-called "organ-on-a-chip" technology, which represents a new avenue in the field of advanced in vitro models, with the potential to revolutionize current approaches to drug screening and toxicology studies. This review aims to highlight recent advances of microfluidic-based devices towards a body-on-a-chip concept, exploring their technology and broad applications in the biomedical field.

Additive manufacturing of polymeric composites from material processing to structural design

Abstract: Polymeric composites with multi-functionality offer significant advantages over metals, including lightweight, high strength and stiffness, corrosion and fatigue resistance, etc. Additively manufactured composites draw intensive attention over the past decade due to that they exhibit the large potential to extend their applications from rapid prototyping to functional end-use components. Moreover, advances in additive manufacturing (AM) open new perspectives for the next generation of design and manufacturing of composites, which possess spatially digitalized and materialized arrangement of material/structure in a voxel-by-voxel manner. This review examines the work performed in this fast-growing field and elaborates its future perspectives and potentials. Specifically, the polymer AM processes incorporating different types of reinforcements are discussed in terms of mechanism, feedstocks, their advantages, and constraints. Then, the AM-driven designs for polymeric composites on multiscale and for multi-functional applications are emphasized. Further, emerging research topics including digital composites, intelligence/data-driven design approaches, and four-dimensional printing are further addressed with the careful analysis of existing gaps and future research trends. Finally, this review is concluded with an outlook on future research opportunities on AM-fabricated composites from design to fabrication. This review aims to provide a comprehensive guide to the stakeholders who want to utilize or develop an AM process for polymeric composites.