KEYWORDS: Video, Printing, Data modeling, Polymers, 3D modeling, Education and training, Video processing, Manufacturing, Deep learning, Photoresist materials
Two-photon 3D printing technology is an additive manufacturing technology that uses the two-photon absorption process of near-infrared radiation to create a three-dimensional micro-nano scale structure with extremely high resolution. However, in the preparation process of two-photon printing, the laser parameters for inducing photopolymerization have a huge impact on the quality of the polymer structure. Therefore, monitoring the quality of the device during the manufacturing process and rationally optimizing the laser parameters are of great significance to the field of additive manufacturing. In this study, we collected video data of different structural devices prepared by self-made photoresist materials under different laser parameters, and used a variety of convolutional neural network variant models to train and verify our collected datasets. The results show that the variant deep learning neural network model can classify the quality of polymer structures in milliseconds, and the test accuracy can reach 95%.
We present a simple yet robust way to fabricate mono-dispersed gas-in-oil-in-water (G/O/W) double emulsions in a non-planar microfluidic device. The microfluidic device is composed of two pieces of chip which make the non-planar structure in microchannel be implemented. By manipulating the flow rate of each phase, the structure of the microbubbles can be tuned. This approach is also valid to the generation of G/W/O double emulsions.
In this paper we consider the dynamic modelling of compliant micropositioning mechanisms using flexure hinges. A simple modelling method is presented that is particularly useful for modelling parallel micropositioning mechanisms. This method is based upon linearisation of the geometric constraint equations of the compliant mechanism. This results in a linear kinematic model, a constant Jacobian and linear dynamic model. To demonstrate the computational simplicity of this methodology it is applied to a four-bar linkage using flexure hinges. Comparisons are made between the simple dynamic model and a complete non-linear model derived using the Lagrangian method. The investigation reveals that this new model is accurate yet computationally efficient and simple to use. The method is then further applied to a parallel 3-degree of freedom (dof) mechanism. It is shown that the method can be simply applied to this more complex parallel mechanism. A dynamic model of this mechanism is desired for use in optimal design and for controller design.
Micromanipulation has enabled numerous technological breakthroughs in recent years, from advances in biotechnology to micro-component assembly. Micromanipulators commonly use piezoelectric actuators (PZT) and a compliant mechanism to provide fine motions with position resolution in the nanometre or even sub-nanometre range. Parallel compliant mechanisms are used to provide motion with multiple degrees-of-freedom (DOF) as parallel mechanisms provide greater rigidity and positioning accuracy than serial mechanisms. However, parallel mechanisms with multiple DOF often have dynamic behavior that is coupled, non-linear and highly complex. This leads to difficulties in modeling and controller design, often requiring sophisticated control techniques such as model-based or neural networks to provide fast, accurate control.
This paper presents the findings of an experimental study into the dynamics of a particular 3 DOF compliant mechanism, specifically considering actuator-space coupling at a range of frequencies and poses. It was expected that the dynamics would be coupled as a dynamic model developed for this mechanism suggested this to be the case. However the experimental results reveal the surprising and useful finding that this mechanism possesses almost completely uncoupled dynamics for the operating bandwidth of the manipulator. This result simplifies the problem of controller design and suggests that the micromanipulator could be effectively controlled using simple independent joint control without requiring development of a decoupling controller.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.