Toshitake Tateno

The Potential of Additive Manufacturing Technology for Realizing a Sustainable Society

Today, additive manufacturing (AM), which refers to a process by which digital design data is used to build up artifacts by decomposing material, is gaining growing interest from industry. The AM’s capability for producing complex structure in extremely small lot size can enable more optimal design for today’s manufacturing products. Through such optimal design of each product, energy and material consumption of society can be significantly reduced. As AM can produce a wide variety of components in one-by-one production, the total number of the products (and components) can be significantly reduced. In addition, the products made by AM can be optimally designed and manufactured for each particular purpose. This implies these products have no unused functions that may consume additional energy and materials. The objective of the paper is to propose the method for evaluating AM’s potential for reducing environmental impact of society considering these factors caused by introducing AM technology into industry.

Geometric Accuracy Evaluation of Fabricated Parts by Additive Manufacturing toward Parallel Fabrication

Most rapid prototyping models are fabricated by additive manufacturing (AM) devices, which are usually called as 3D-printers. The AM models are expected to be used as practical parts for small batch manufacturing and maintenance parts supply. The main problem of AM for practical parts depends on processing accuracy and productivity. To compete with these problems, the parallel fabrication is considered. In this paper, after the concept of the parallel fabrication is introduced, the geometric accuracy of AM parts is evaluated and discussed from viewpoints of shape and processing. Two primitive shapes, which are a cube and a cylinder, are chosen as evaluation objects. These models are fabricated by two different type AM processing, which are Stereo Lithography (SL) and Fused Deposition Modeling (FDM). The geometry of objects is measured by a contact type 3D measurement system. As a result, characteristics of geometric error, which depend on shape features and AM processing, were found. The design guideline for contact surfaces between segmented parts is discussed.

Web-based mechatronic simulation environment for open collaborative design

Recently, a new product design and development style, in which external engineers at remote place can join the project for a collaborative work, is noticed as one type of the open innovation. In this paper, a web-based mechatronic simulation environment is improved by the realization of a new prototype implementation scheme. Such one environment can be used for design of products with both mechanical and electrical structure and their behaviors can be simulated together. The scheme is one of coupled simulations over multi-disciplinal fields. As an example, a simple environment for a positioning machine design as a mechatronic product is implemented. Through a case study to model and simulate a positioning table motion, the effect of the proposed environment is verified.

Architecture of Sensor Network System for Promoting Condition-Based Maintenance and Reuse

Considering the environmental load of material and energy consumption, many approaches to product design and manufacture have been discussed from an ecological viewpoint. In this paper, we propose the architecture of a sensor network system that promotes condition-based maintenance and reuse in order to reduce the environmental load in product manufacture and use. The system architecture stands on an agent-based sensor network and a modular reusable design. In this system, sensor data are used not only for condition-based maintenance but also for reuse management since they enable the estimation of product conditions that are indices for deciding a lifecycle option and a reuse plan. As a simple realization model of the proposed architecture, a motor-assisted bicycle CBM and reuse support system is developed by using wireless small sensor network and network agent systems. The system monitors product conditions and searches the next owner of each module for promoting reuse and avoiding product waste as much as possible. Case studies show some practical use and merits of this architecture.© 2009 ASME

Vibration Characteristics of Unit Cell Structures Fabricated by Multi-Material Additive Manufacturing

Natural vibration frequency of objects fabricated by Additive Manufacturing (AM) is experimentally investigated. In this paper, several beam structures consisting of square unit cells are fabricated by material extrusion type AM, which is usually called Fused Deposition Modeling (FDM). The target object is oscillated by a magnetic motor and the amplitude of vibration is measured with a laser vibrometer. The effects of deposition direction and material composition on the primary natural frequency are discussed. These factors can be controlled by using AM. The experimental results showed that the frequency obviously depends on both deposition direction and material composition. The possibility of a vibration design method in product design was indicated.

Biodegradable Mechatronic Products by Additive Manufacturing

Mechatronic products are necessary for our life and industrial factories. Recently, most mechatronic products have self-monitoring function, which is based on the sensor data. This function is useful not only for efficient maintenance but also efficient product recovery. However, additional sensing and communication devices lead to increase of environmental costs by themselves. Therefore, eco-design of mechatronic products including these devices is expected. In this paper, the use of additive manufacturing (AM) with biodegradable materials is proposed. First, the realization type of the product is defined as the proposition of this paper. Then, characteristics of AM and biodegradable materials for contributing to reduce environmental costs are analyzed. Additive manufacturing (AM), which is usually called as 3D printing, has naturally advantage in eco-design. Biodegradable material is also known to reduce energy for product disposal processes. However, it is shown that the combinational use of them promotes the effectiveness. Next, the comparison between the conventional product and the present product of the production and disposal processes is discussed by using an electronic print board. The result shows that the production process becomes remarkably simple and the recovery process becomes efficient. Finally, a realization example is introduced. An RFID antenna module fabricated with PLA and an original biodegradable electric conductive gel is shown. This module is confirmed to work certainly by connecting with an IC chip as a mass-production module. The realization of the proposed product is discussed.

Performance improvement of microbial fuel cells by using ultrasonic vibration

Microbial fuel cells (MFC) are expected as a type of electric power generation that does not depend on fossil fuel. Many challenges have been reported to increase the performance. However, there are few researches about MFC or MFC systems from mechanical device points of view. This research proposes and investigates a new idea to improve the performance by use of ultrasonic vibrations generated by piezo electronic devices. In this paper, possible effects of the ultrasonic vibrations are introduced, and a system structure for this application is discussed. As basic experiments, the effects of ultrasonic vibrations on phototrophic bacteria, are examined.

Micro-Object Orientation Control by Using Different Vibration Modes of Board Stage

This paper deals with an orientation control method for micro objects, which have a size in the order of 100 micro meters, by using a board stage that is vibrated in the natural frequencies of various vibration modes. Orientation control is important for manufacturing processes, such as the assembling of small parts. Since it is difficult to grip and to manipulate micro objects, a simple and reliable method is desired. In this paper, the vibration mode is used for generating different motions of the stage and for controlling the orientation of the objects on the stage. Since each vibration mode has a unique vibration motion, different motions can be selected by choosing the vibration frequency. In order to design the stage so that the objects turn toward target direction, Finite Element Method (FEM) analysis was applied. And, the designed vibration stage was fabricated using a stainless steel thin plate. Experimental results showed that the actual vibration is similar with the simulation results. As an example of the orientation control of the micro objects, some small electronics parts were tested and they could be turned toward the target directions.