Fused deposition modelling (FDM) is the most economical additive manufacturing technique. The purpose of this paper is to describe a detailed review of this technique. Total 211 research papers published during the past 26 years, that is, from the year 1994 to 2019 are critically reviewed. Based on the literature review, research gaps are identified and the scope for future work is discussed.,Literature review in the domain of FDM is categorized into five sections – (i) process parameter optimization, (ii) environmental factors affecting the quality of printed parts, (iii) post-production finishing techniques to improve quality of parts, (iv) numerical simulation of process and (iv) recent advances in FDM. Summary of major research work in FDM is presented in tabular form.,Based on literature review, research gaps are identified and scope of future work in FDM along with roadmap is discussed.,In the present paper, literature related to chemical, electric and magnetic properties of FDM parts made up of various filament feedstock materials is not reviewed.,This is a comprehensive literature review in the domain of FDM focused on identifying the direction for future work to enhance the acceptability of FDM printed parts in industries.

Fused deposition modelling: a review

In conventional classification, soft robots feature mechanical compliance as the main distinguishing factor from traditional robots made of rigid materials. Recent advances in functional soft materials have facilitated the emergence of a new class of soft robots capable of tether-free actuation in response to external stimuli such as heat, light, solvent, or electric or magnetic field. Among the various types of stimuli-responsive materials, magnetic soft materials have shown remarkable progress in their design and fabrication, leading to the development of magnetic soft robots with unique advantages and potential for many important applications. However, the field of magnetic soft robots is still in its infancy and requires further advancements in terms of design principles, fabrication methods, control mechanisms, and sensing modalities. Successful future development of magnetic soft robots would require a comprehensive understanding of the fundamental principle of magnetic actuation, as well as the physical properties and behavior of magnetic soft materials. In this review, we discuss recent progress in the design and fabrication, modeling and simulation, and actuation and control of magnetic soft materials and robots. We then give a set of design guidelines for optimal actuation performance of magnetic soft materials. Lastly, we summarize potential biomedical applications of magnetic soft robots and provide our perspectives on next-generation magnetic soft robots.

Magnetic Soft Materials and Robots.

Nondestructive testing (NDT) for casting aluminum parts is an essential quality management procedure. In order to avoid the effects of human fatigue and improve detection accuracy, intelligent visual inspection systems are adopted on production lines. Conventional methods of defect detection can require heavy image pre-processing and feature extraction. This paper proposes a defect detection system based on X-ray oriented deep learning, which focuses on approaches that improve the detection accuracy at both the algorithm and data augmentation levels. Feature Pyramid Network (FPN) was primarily adopted for algorithm modification, which proved to be better suited for detecting small defects than Faster R-CNN, with a 40.9% improvement of the mean of Average Precision (mAP) value. In the final regression and classification stage, RoIAlign indicated apparent accuracy improvement in bounding boxes location compared with RoI pooling, which could increase accuracy by 23.6% under Faster R-CNN. Furthermore, different data augmentation methods compensated for the lack of datasets in X-ray image defect detection. Experiments found that an optimal mAP value existed, instead of it continuously increasing with the number of datasets rising for each data augmentation method. Research indicated that the three proposed improvement approaches performed better than baseline Faster R-CNN in X-ray image defect detection of automobile aluminum casting parts.

Approaches for improvement of the X-ray image defect detection of automobile casting aluminum parts based on deep learning

Manipulation of micro- and nano-objects has been widely studied in the past two decades due to its potential applications in various fields. In this review, we focus primarily on magnetic field-based manipulation techniques, which have shown to be extremely promising for the motion control of such objects at small scales. We start from the fundamental analysis of the magnetic forces and the torques acting on objects subjected to magnetic fields, and then summarize the most recent contributions in magnetic manipulation employed in four typical applications: micro-mixing, trapping, colloidal assembly, and object transport. Moreover, how magnetic fields can be applied to object manipulation and the physical principles underlying these manipulation processes are highlighted.

Recent advances in manipulation of micro- and nano-objects with magnetic fields at small scales

Surface modification and selective flotation of waste plastics for effective recycling——a review

3D Printing of Functional Magnetic Materials: From Design to Applications

Magnetic levitation is a recent research hot spot; however, most of the extant configurations use two magnets with like poles facing each other. This paper proposes a novel magnetic levitation configuration that is based on a single ring magnet, and this configuration opens a wide operational space that enables object manipulation and density-based measurement. We develop a mathematical model to calculate the magnetic field around the magnet and to numerically correlate the levitation height and density of the object. Experimental results prove that this novel configuration can achieve a high accuracy (±0.0005 to ±0.0078 g/cm3) in density measurement for small-sized (∼5 μL) samples. It can manipulate particles, powders, and oil droplets effectively without any direct contact, and it has high sensitivity in the separation of multiple diamagnetic objects with slight differences in densities as well. The accuracy and sensitivity of the proposed configuration are both higher than those of the extant configura...

Single-Ring Magnetic Levitation Configuration for Object Manipulation and Density-Based Measurement.

Non-destructive measurement of three-dimensional polymeric parts by magneto-Archimedes levitation

Enlarging density measurement range for polymers by horizontal magneto-Archimedes levitation

This study presents a magnetic levitation device for measuring density with high accuracy and versatility, and of low cost. Samples that are immersed in paramagnetic medium can be levitated at some equilibrium positions between two identical NdFeB magnets with like-poles facing each other. The method measures density without acquiring the sample’s volume, therefore it can be used to deal with tiny particles (

Chengqian Zhang

Papers

3D Printing of Functional Magnetic Materials: From Design to Applications

Single-Ring Magnetic Levitation Configuration for Object Manipulation and Density-Based Measurement.

Non-destructive measurement of three-dimensional polymeric parts by magneto-Archimedes levitation

Enlarging density measurement range for polymers by horizontal magneto-Archimedes levitation

An accurate and versatile density measurement device: Magnetic levitation