Searched for: department%3A%22Precision%255C%2Band%255C%2BMicrosystems%255C%2BEngineering%22
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Boogaard, Bob (author), Tas, Ali (author), Nijssen, J.P.A. (author), Broeren, F.G.J. (author), van den Dobbelsteen, J.J. (author), Verhoeven, Vincent (author), Pluim, Jip (author), Dekker, Sing (author), Snijder, Eric J. (author), van Hemert, Martijn J. (author), Herfst, Sander (author)
The SARS-CoV-2 pandemic resulted in shortages of production and test capacity of FFP2-respirators. Such facemasks are required to be worn by healthcare professionals when performing aerosol-generating procedures on COVID-19 patients. In response to the high demand and short supply, we designed three models of facemasks that are suitable for...
journal article 2021
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Rommers, J. (author), van der Wijk, V. (author), Herder, J.L. (author)
In this paper we present two new designs of spherical flexure joints, which are the compliant equivalent of a traditional ball-and-socket joint. The designs are formed by tetrahedron-shaped elements, each composed of three blade flexures with a trapezoidal shape, that are connected in series without intermediate bodies. This is new with...
journal article 2021
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Kuppens, P.R. (author), Bessa, M.A. (author), Herder, J.L. (author), Hopkins, J. B. (author)
We introduce two essential building blocks with binary stiffness for mechanical digital machines. The large scale fully compliant mechanisms have rectilinear and rotational kinematics and use a new V-shaped negative stiffness structure to create two extreme states of stiffness by static balancing. The use of a mechanical bistable switch...
journal article 2021
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de Jong, J. J. (author), Müller, A. (author), Herder, J.L. (author)
Dynamic balance eliminates the fluctuating reaction forces and moments induced by high-speed robots that would otherwise cause undesired base vibrations, noise and accuracy loss. Many balancing procedures, such as the addition of counter-rotating inertia wheels, increase the complexity and motor torques. There exist, however, a small set of...
journal article 2021
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Amoozandeh Nobaveh, A. (author), Radaelli, G. (author), Herder, J.L. (author)
A design tool for passive wrist support using compliant spatial beams as gravity balancer is presented. The aim of this assistive device is to reduce required effort for pronation-supination and flexion-extension by 70% to help patients with muscular weakness keeping their hand’s posture and doing daily tasks, while the forearm is rested. To...
conference paper 2021
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Amoozandeh Nobaveh, A. (author), Radaelli, G. (author), Herder, J.L. (author)
A method to achieve symmetric kinetostatic behaviour in an extensive working range at the endpoint of an asymmetric spatial beam, using cross-section optimization, is presented. The objective function of the optimization is defined as expanding the beam working range to the desired region, simultaneously maximizing symmetric behaviour in it....
book chapter 2021
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Borcea, Ciprian S. (author), Broeren, F.G.J. (author), Herder, J.L. (author), Streinu, Ileana (author), van der Wijk, V. (author)
Auxetic behavior refers to lateral widening upon stretching or, in reverse, lateral shrinking upon compression. When an initially auxetic structure is actuated by compression or extension, it will not necessarily remain auxetic for larger deformations. In this paper, we investigate the auxetic range in the deformation of a periodic framework...
journal article 2021
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Wang, M. (author), Ge, Daohan (author), Zhang, Liqiang (author), Herder, J.L. (author)
Compliant micromechanisms (CMMs) acquire mobility from the deflection of elastic members and have been proven to be robust by millions of silicon MEMS devices. However, the limited deflection of silicon impedes the realization of more sophisticated CMMs, which often require larger deflections. Recently, some novel manufacturing processes have...
review 2021
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Kuppens, P.R. (author), Bessa, M.A. (author), Herder, J.L. (author), Hopkins, J. B. (author)
Stiffness in compliant mechanisms can be dramatically altered and even eliminated entirely by using static balancing. This requires elastic energy to be inserted before operation, which is most often done with an additional device or preloading assembly. Adding such devices contrasts starkly with primary motivations for using compliant...
journal article 2021
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Tschiersky, Martin (author), Hekman, Edsko E.G. (author), Brouwer, Dannis M. (author), Herder, J.L. (author), Suzumori, Koichi (author)
In this letter we demonstrate a pneumatic bending actuator for upper-limb assistive wearable robots which uses thin McKibben muscles in combination with a flexure strip. The actuator features both active soft actuation and passive gravity support, and in terms of force transmission bridges the gap between the classic rigid type actuators and...
journal article 2020
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Bos, R.A. (author), Nizamis, Kostas (author), Koopman, Bart F.J.M. (author), Herder, J.L. (author), Sartori, Massimo (author), Plettenburg, D.H. (author)
With recent improvements in healthcare, individuals with Duchenne muscular dystrophy (DMD) have prolonged life expectancy, and it is therefore vital to preserve their independence. Hand function plays a central role in maintaining independence in daily living. This requires sufficient grip force and the ability to modulate it with no...
journal article 2020
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Blad, Thijs (author), Nijssen, J.P.A. (author), Broeren, F.G.J. (author), Boogaard, Bob (author), Lampaert, S.G.E. (author), van den Toorn, Stefan (author), van den Dobbelsteen, J.J. (author)
Introduction: The current COVID-19 pandemic has caused large shortages in personal protective equipment, leading to hospitals buying their supplies from alternative suppliers or even reusing single-use items. Equipment from these alternative sources first needs to be tested to ensure that they properly protect the clinicians that depend on...
journal article 2020
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Hoevenaars, A.G.L. (author), Krut, S. (author), Herder, J.L. (author)
The dynamic performance of a parallel manipulator is often limited by its natural frequencies. These frequencies are a result of the controlled actuator stiffness and the mechanical design. Typically, only the lowest natural frequencies are of interest. However, existing methods to analyze natural frequencies of parallel manipulators with...
journal article 2020
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Broeren, F.G.J. (author), van der Wijk, V. (author), Herder, J.L. (author)
In this paper, a pseudo-rigid body model is proposed for the analysis of a spatial mechanical metamaterial and its application is demonstrated. Using this model, the post-buckling behavior of the mechanical metamaterial can be determined without the need to consider the whole elastic structure, e.g., using finite-element procedures. This is done...
journal article 2020
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Broeren, F.G.J. (author), van de Sande, W.W.P.J. (author), van der Wijk, V. (author), Herder, J.L. (author)
Dilational structures can change in size without changing their shape. Current dilational designs are only suitable for specific shapes or curvatures and often require parts of the structure to move perpendicular to the dilational surface, thereby occupying part of the enclosed volume. Here, we present a general method for creating dilational...
journal article 2019
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Bos, R.A. (author), Plettenburg, D.H. (author), Herder, J.L. (author)
While designing a dynamic hand orthosis to assist during activities of daily living, the designer has to know whether a concept will have sufficient grasp performance to support these activities. This is often estimated by measuring the interaction force at the contact interface. However, this requires a prototyping step and limits the...
journal article 2019
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Kuppens, P.R. (author), Herder, J.L. (author), Tolou, N. (author)
Stiffness in compliant micro mechanisms can negatively affect performance. Current methods for stiffness reduction in micro electro mechanical systems (MEMS) consume power, have a large footprint or are relatively complex to manufacture. In this paper stiffness is reduced by static balancing. A building block commonly used for stiffness...
journal article 2019
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de Jong, J.J. (author), van Dijk, J. (author), Herder, J.L. (author)
Fast-moving industrial robots exert large varying reaction forces and moments on their base frame, inducing vibrations, wear and accuracy degeneration. These shaking forces and moments can be eliminated by a specific design of the mass distribution of the robot links, resulting in a dynamically balanced mechanism. Obtaining the conditions for...
journal article 2019
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Farhadi Machekposhti, D. (author), Herder, J.L. (author), Tolou, N. (author)
Microtransmission mechanisms made of elastic materials present an opportunity for exploring scalable mechanical systems integrated with sophisticated functionalities. This paper shows how the fundamentally limited range of motion in elastic mechanisms can be circumvented to create a frequency doubling functionality analog to angular velocity...
journal article 2019
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Tschiersky, Martin (author), Hekman, Edsko E.G. (author), Brouwer, Dannis M. (author), Herder, J.L. (author)
In this paper, we propose a flexure spring based gravity compensation device which provides assistance to lift the forearm. Three different spring designs are obtained and evaluated. The synthesis method to obtain these is explained in detail and an experimental evaluation validates the desired gravity balancing properties. It is found that in...
journal article 2019
Searched for: department%3A%22Precision%255C%2Band%255C%2BMicrosystems%255C%2BEngineering%22
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