The past few decades have seen substantial growth in Additive Manufacturing (AM) technologies. However, this growth has mainly been process-driven. The evolution of engineering design to take advantage of the possibilities afforded by AM and to manage the constraints associated with the technology has lagged behind. This paper presents the major opportunities, constraints, and economic considerations for Design for Additive Manufacturing. It explores issues related to design and redesign for direct and indirect AM production. It also highlights key industrial applications, outlines future challenges, and identifies promising directions for research and the exploitation of AM's full potential in industry.

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Design for additive manufacturing: trends, opportunities, considerations, and constraints

Advances in soft robotics, materials science, and stretchable electronics have enabled rapid progress in soft grippers. Here, a critical overview of soft robotic grippers is presented, covering different material sets, physical principles, and device architectures. Soft gripping can be categorized into three technologies, enabling grasping by: a) actuation, b) controlled stiffness, and c) controlled adhesion. A comprehensive review of each type is presented. Compared to rigid grippers, end-effectors fabricated from flexible and soft components can often grasp or manipulate a larger variety of objects. Such grippers are an example of morphological computation, where control complexity is greatly reduced by material softness and mechanical compliance. Advanced materials and soft components, in particular silicone elastomers, shape memory materials, and active polymers and gels, are increasingly investigated for the design of lighter, simpler, and more universal grippers, using the inherent functionality of the materials. Embedding stretchable distributed sensors in or on soft grippers greatly enhances the ways in which the grippers interact with objects. Challenges for soft grippers include miniaturization, robustness, speed, integration of sensing, and control. Improved materials, processing methods, and sensing play an important role in future research.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201707035

Soft Robotic Grippers.

An overview on 3D printing technology: Technological, materials, and applications

In an effort to improve customization for today's highly competitive global marketplace, many companies are utilizing product families and platform-based product development to increase variety, shorten lead times, and reduce costs The key to a successful product family is the product platform from which it is derived either by adding, removing, or substituting one or more modules to the platform or by scaling the platform in one or more dimensions to target specific market niches This nascent field of engineering design has matured rapidly in the past decade, and this paper provides a comprehensive review of the flurry of research activity that has occurred during that time to facilitate product family design and platform-based product development for mass customization Techniques for identifying platform leveraging strategies within a product family are reviewed along with metrics for assessing the effectiveness of product platforms and product families Special emphasis is placed on optimization approaches and artificial intelligence techniques to assist in the process of product family design and platform-based product development Web-based systems for product platform customization are also discussed Examples from both industry and academia are presented throughout the paper to highlight the benefits of product families and product platforms The paper concludes with a discussion of potential areas of research to help bridge the gap between planning and managing families of products and designing and manufacturing them

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Product platform design and customization: Status and promise

Design for manufacture and assembly (DFM) has typically meant that designers should tailor their designs to eliminate manufacturing difficulties and minimize manufacturing, assembly, and logistics costs. However, the capabilities of additive manufacturing technologies provide an opportunity to rethink DFM to take advantage of the unique capabilities of these technologies. As mentioned in Chap. 16, several companies are now using AM technologies for production manufacturing. For example, Siemens, Phonak, Widex, and the other hearing aid manufacturers use selective laser sintering and stereolithography machines to produce hearing aid shells; Align Technology uses stereolithography to fabricate molds for producing clear dental braces (“aligners”); and Boeing and its suppliers use polymer powder bed fusion (PBF) to produce ducts and similar parts for F-17 fighter jets. For hearing aids and dental aligners, AM machines enable manufacturing of tens to hundreds of thousands of parts, where each part is uniquely customized based upon person-specific geometric data. In the case of aircraft components, AM technology enables low-volume manufacturing, easy integration of design changes and, at least as importantly, piece part reductions to greatly simplify product assembly.

Design for Additive Manufacturing

A Review of Data-Driven Machinery Fault Diagnosis Using Machine Learning Algorithms

Soft actuators and robotics have been widely researched in recent years mainly due to their compliance to environments and safe interaction with humans. However, the need of tether and low energy e...

/pdf/a-novel-tendon-driven-soft-actuator-with-self-pumping-2o8xwhvitl.pdf

A Novel Tendon-Driven Soft Actuator with Self-Pumping Property

Fluidic and tendon driven actuators are widely applied in soft robotic hand design. Fluidic actuated soft robotic hands are highly compliant and can adapt to various objects. Tendon driven soft robotic hands are easier to control and have high dexterity and large force output, however, they are less compliant than fluidic actuated ones. Most robotic hands are designed with only one actuation method. Combining both actuation methods can tap the advantages and make up each other's limitations but at the expense of more complicated design and control. In this research, we propose a simple dual-mode actuator that provides both fluidic and tendon actuation. The two actuation modes are achieved simultaneously by twisting an elastic tube filled with gas, liquid, or even a combination. The soft robotic finger, designed as a fluidic elastomer actuator (FEA), is actuated by the fluid displaced from tube twisting, as well as by the tendon due to tube contraction in twisting. The tendon drives a compliant metacarpophalangeal (MCP) joint of the finger in order to provide a large bending angle and bending force to finger. Compared to an FEA soft finger, the proposed design can effectively increase the bending angle up to 150% (from 170 degrees to 260 degrees), and the blocking force up to 134% (from 3.2N to 4.3N). A soft robotic hand prototype with dual-mode actuators design is made for various grasping demonstrations.

A Dual-Mode Actuator for Soft Robotic Hand

When doing femur fracture reduction surgery, both patient and surgeon are exposed to a great amount of radiation, which is harmful to their health. Computer assisted orthopaedic surgery (CAOS) is a less invasive approach for its ability to reduce the usage of image intensifier. Various robots have been developed for femur fracture reduction surgery. Most of these robots are beared on serial architecture. The low transportable load and poor accuracy are both inherent in serial robots, which makes them inappropriate for femur fracture reduction. Some fully parallel robots using the “Stewart platform” are also developed for femur fracture reduction, but their restricted workspace limits their performance. To balance the accuracy and workspace, a new hybrid robot with six degree-of-freedom is reported here. It possesses the characteristic of the Cartesian coordinate robot, all the movement of the actuators are linear, which makes its movement smooth for low speed fracture reduction procedure.

Development of a six degree of freedom (DOF) hybrid robot for femur shaft fracture reduction

Modern society is fueled by very comprehensive grids of gas and liquid supply pipelines. The frequent inspection and maintenance of such pipeline grids is not a trivial task. It has been demonstrated that such task is best performed by using in-pipe robots. In this paper, a novel inchworm robot design and its optimized motion planning are presented. The proposed design uses a helical drive for both gripping and locomotion of the robot. The extension and retraction between inchworm segments are facilitated by conic springs as they can store strain energy. The proposed inchworm robot can also be made very compact without sacrificing stroke length as conic springs can be easily designed with telescopic feature. To generate inchworm motion, a sinusoidal velocity pattern is planned for each segment. The frequency of the velocity pattern is optimized using a genetic algorithm (GA). The optimization result from the GA method has been validated using a traditional gradient based method.

Yonghua Chen

Papers

A Review of Data-Driven Machinery Fault Diagnosis Using Machine Learning Algorithms

A Novel Tendon-Driven Soft Actuator with Self-Pumping Property

A Dual-Mode Actuator for Soft Robotic Hand

Development of a six degree of freedom (DOF) hybrid robot for femur shaft fracture reduction

Optimized inchworm motion planning for a novel in-pipe robot: