Olaf Diegel

Sensory system integration of the designed mechatronics Touch Hand

Purpose – This paper aims to explore the electronic design of the Touch Hand: a low-cost electrically powered prosthetic hand. The hand is equipped with an array of sensors allowing for position control and haptic sensation. Pressure sensors are used on the fingertips to detect grip force. A temperature sensor placed in the fingertip is used to measure the contact temperature of objects. Investigations are made into the use of cantilever vibration sensors to detect surface texture and object slippage. The hand is capable of performing a lateral grip of 3.7 N, a power grip of 19.5 N and to passively hold a weight of up to 8 kg with a hook grip. The hand is also tested on an amputee and used to perform basic tasks. The amputee took 30 min to learn how to operate the hands basic gripping functions. Design/methodology/approach – Problems of previous prosthetic hands were investigated, followed by ways to improve or have similar capabilities, yet keeping in mind to reduce the price. The hand was then designed,...

Reconfigurable Mechatronic Robotic Plug-and-Play Controller

In today’s manufacturing community, flexible manufacturing systems (FMS) are becoming important. There is a global trend towards flexible manufacturing systems with an increasing number of countr ies competing for a share of the world market. FMS are increasingly required for companies to meet the demand for high quality, reasonably priced products. FMS allow a manufacturer to quickly change processes or operations to produce any product, at any time, while striving to keep the processes economical. To remain competitive companies should be replacing or upgrading old, obsolete methods, processes, and systems with the latest advances in manufacturing technology. This competition within the manufacturing industry has led to a focus on producing high quality parts quickly and accurately. The quality of products, along with the increased productivity necessary to compete globally, has led more and more manufacturers to introduce advanced manufacturing technologies in their factories. In order for these advanced manufacturing technologies to be accepted by manufacturing companies, they need to be able to implement the new technologies and their processes as quickly as possible so as to keep manufacturing down-time to a minimum. This allows the manufacturer to respond quickly and with increased flexibility to market needs. Such is the need for FMS.

Additive manufacturing and its effect on sustainable design

‘Sustainability’ is an emerging issue that product development engineers must engage with to remain relevant, competitive and, most importantly, responsible. Yet, on examining the term ‘sustainable’, a plethora of definitions emerges, many of which are contradictory and confusing. This confusion and a general lack of understanding means that sustainability often gets relegated to an afterthought or a buzz-word used on marketing material, no matter how ‘sustainable’ the product actually is. The role of the ‘sustainable’ product developer is to look for new opportunities to design products that minimize harmful effects on the environment and to seek to develop environmental, social, and economically beneficial product solutions. The advent of additive manufacturing technologies presents a number of opportunities that have the potential to benefit designers greatly and contribute to the sustainability of products. Products can be extensively customized for the user, thus potentially increasing their desirability, pleasure and attachment—and therefore longevity. Additive manufacturing technologies have also removed many of the manufacturing restrictions that may previously have compromised a designer’s ability to make the product they imagined which, once again, can increase product desirability, pleasure and attachment. As additive manufacturing technologies evolve, design methodologies for lightweighting, such as topology optimization, become more advanced, more new materials become available, and multiple material technologies are developed, the field of product design has the potential for great change. This chapter examines aspects of additive manufacturing from a sustainable design perspective and looks at the potential to create entirely new business models that could bring about the sustainable design of consumer products. It first gives a brief literature review both on sustainable product development and on additive manufacturing, and then examines several case study products that were made with additive manufacturing. It concludes that there is a likelihood that additive manufacturing allows more sustainable products to be developed, but also that more quantifiable research is needed in the area to allow designers to exploit better the features of additive manufacturing that can maximize sustainability.

Teaching Design for Additive Manufacturing Through Problem-Based Learning

Additive Manufacturing (AM) is a technology that, while removing many of the constraints of traditional manufacturing, imposes some new constraints of its own. Because of this, engineers and designers need to be taught a new set of skills in design for additive manufacturing (DfAM) in order to become competent in designing parts that maximize the benefits offered by AM. Around the world, universities and organizations are beginning to offer courses in DfAM to improve the skills of modern engineers and designers. Staff at Lund University, in Sweden, have begun to offer such DfAM courses to industry that use problem-based learning (PBL) as the pedagogical approach to teaching DfAM in a more effective way. This chapter describes how these courses have been implemented, and how they have benefitted from the PBL teaching approach.

A process for estimating minimum feature size in selective laser sintering

Purpose Manufacturer specifications for the resolution of an additive manufacturing (AM) machine can be ten times smaller (more optimistic) than the actual size of manufacturable features. Existing methods used to establish a manufacturable design rule-set are conservative piecewise-constant approximations. This paper aims to evaluate the effectiveness of a first-order model for producing improved design rule-sets for feature manufacturability, accounting for process variation. Design/methodology/approach A framework is presented which uses an interpolation method and a statistical model to estimate the minimum size for a wide range of features from a set of iterative experiments. Findings For an SLS process, using this approach improves the accuracy and reliability of minimum feature size estimates for a wider variety of features than assessed by most existing test artifacts. Research limitations/implications More research is needed to provide better interpolation models, broaden applicability and account for additional geometric and process parameters which significantly impact the results. This research focuses on manufacturability and does not address dimensional accuracy of the features produced. Practical implications An application to the design of thin channels in a prosthetic hand shows the utility of the results in a real-world scenario. Originality/value This study is among the first to investigate statistical variation of “pass/fail” features in AM process characterization, propose a means of estimating minimum feature sizes for shapes not directly tested and incorporate a more efficient iterative experimental protocol.

Cell immobilization on 3D-printed matrices : A model study on propionic acid fermentation

This study uses three-dimensional (3D) printing technology as a tool for designing carriers for immobilization of microbial cells for bioprocesses. Production of propionic acid from glucose by immobilized Propionibacterium sp. cells was studied as a model system. For cell adsorption, the 3D-printed nylon beads were added to the culture medium during 3 rounds of cell cultivation. Cell adsorption and fermentation kinetics were similar irrespective of the bead size and lattice structure. The cells bound to 15 mm beads exhibited reduced fermentation time as compared to free cell fermentations; maximum productivity and propionic acid titer of 0.46 g/L h and 25.8 g/L, respectively, were obtained. Treatment of the beads with polyethyleneimine improved cell-matrix binding, but lowered the productivity perhaps due to inhibitory effect of the polycation. Scanning electron micrographs revealed the cells to be located in crevices of the beads, but were more uniformly distributed on PEI-coated carrier indicating charge-charge interaction.