scholarly journals Toward Inkjet Additive Manufacturing Directly Onto Human Anatomy

Author(s):  
Reed A. Johnson ◽  
John J. O’Neill ◽  
Rodney L. Dockter ◽  
Timothy M. Kowalewski

Bioprinting technology has been rapidly increasing in popularity in the field of tissue engineering. Potential applications include tissue or organ regeneration, creation of biometric multi-layered skin tissue, and burn wound treatment [1]. Recent work has shown that living cells can be successfully applied using inkjet heads without damaging the cells [2]. Electrostatically driven inkjet systems have the benefit of not generating significant heat and therefore do not damage the cell structure. Inkjets have the additional benefit of depositing small droplets with micrometer resolution and therefore can be used to build up tissue like structures. Previous attempts at tracking and drawing on a hand include either direct contact with the hand [3] or tracking the hand only in two degrees of freedom [4]. In this work we present an approach to track a hand with three degrees of freedom and accurately apply a substance contact free to the hand in a desired pattern using a bioprinting compatible inkjet. The third degree of freedom, in this case depth from the hand surface, provides improved control over the distance between the inkjet head and object, thus increasing deposition accuracy.

1995 ◽  
Vol 117 (3) ◽  
pp. 378-388 ◽  
Author(s):  
R. B. Roth ◽  
Kok-Meng Lee

This paper presents the basis for optimizing the design of a three degrees-of-freedom (DOF) variable reluctance (VR) spherical motor which offers some attractive features by combining pitch, roll, and yaw motion in a single joint. The spherical wrist motor offers a major performance advantage in trajectory planning and control as compared to the popular three-consecutive-rotational joint wrist. Since an improved performance estimate is required, a method for optimizing the VR spherical motor’s magnetics was developed. This paper begins with a presentation of the geometrical independent and dependent variables which fully described the design of a VR spherical motor. These variables are derived from examination of the torque prediction model. Next, a complete set of constraint equations governing geometry, thermal limitations, amplifier specifications, iron saturation, and leakage flux are derived. Finally, an example problem is presented where the motor’s geometry is determined by maximizing the output torque at one rotor position. The concept of developing a spherical motor with uniform torque characteristics is discussed with respect to the optimization methodology. It is expected that the resulting analysis will improve the analytical torque prediction model by the inclusion of constraint equations, aid in developing future VR spherical motor designs, improve estimates of performance, and therefore will offer better insight into potential applications.


2018 ◽  
Vol 51 (13) ◽  
pp. 372-377 ◽  
Author(s):  
Juan E. Andrade García ◽  
Alejandra Ferreira de Loza ◽  
Luis T. Aguilar ◽  
Ramón I. Verdés

Author(s):  
Ouyang Qianqian ◽  
Kong Songzhi ◽  
Huang Yongmei ◽  
Ju Xianghong ◽  
Li Sidong ◽  
...  
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Author(s):  
A. H. S. Iyer ◽  
M. H. Colliander

Abstract Background The trend in miniaturisation of structural components and continuous development of more advanced crystal plasticity models point towards the need for understanding cyclic properties of engineering materials at the microscale. Though the technology of focused ion beam milling enables the preparation of micron-sized samples for mechanical testing using nanoindenters, much of the focus has been on monotonic testing since the limited 1D motion of nanoindenters imposes restrictions on both sample preparation and cyclic testing. Objective/Methods In this work, we present an approach for cyclic microcantilever bending using a micromanipulator setup having three degrees of freedom, thereby offering more flexibility. Results The method has been demonstrated and validated by cyclic bending of Alloy 718plus microcantilevers prepared on a bulk specimen. The experiments reveal that this method is reliable and produces results that are comparable to a nanoindenter setup. Conclusions Due to the flexibility of the method, it offers straightforward testing of cantilevers manufactured at arbitrary position on bulk samples with fully reversed plastic deformation. Specific microstructural features, e.g., selected orientations, grain boundaries, phase boundaries etc., can therefore be easily targeted.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xiaohui Liu ◽  
Ming Zou ◽  
Chuan Wu ◽  
Mengqi Cai ◽  
Guangyun Min ◽  
...  

A new quad bundle conductor galloping model considering wake effect is proposed to solve the problem of different aerodynamic coefficients of each subconductor of iced quad bundle conductor. Based on the quasistatic theory, a new 3-DOF (three degrees of freedom) galloping model of iced quad bundle conductors is established, which can accurately reflect the energy transfer and galloping of quad bundle conductor in three directions. After a series of formula derivations, the conductor stability judgment formula is obtained. In the wind tunnel test, according to the actual engineering situation, different variables are set up to accurately simulate the galloping of iced quad bundle conductor under the wind, and the aerodynamic coefficient is obtained. Finally, according to the stability judgment formula of this paper, calculate the critical wind speed of conductor galloping through programming. The dates of wind tunnel test and calculation in this paper can be used in the antigalloping design of transmission lines.


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