3D Bioplotter Research Papers

Displaying all papers by A. Zolfagharian (9 results)

Topology-Optimized 4D Printing of a Soft Actuator

Acta Mechanica Solida Sinica 2019

Soft robots and actuators are emerging devices providing more capabilities in the field of robotics. More flexibility and compliance attributing to soft functional materials used in the fabrication of these devices make them ideal for delivering delicate tasks in fragile environments, such as food and biomedical sectors. Yet, the intuitive nonlinearity of soft functional materials and their anisotropic actuation in compliant mechanisms constitute an existent challenge in improving their performance. Topology optimization (TO) along with four-dimensional (4D) printing is a powerful digital tool that can be used to obtain optimal internal architectures for the efficient performance of porous soft actuators….

System identification and robust tracking of a 3D printed soft actuator

Smart Materials and Structures 2019 Volume 28, Article 075025

Current three-dimensional (3D) printing allows for the fabrication of controllable 3D printed soft actuators with growing applications in soft robotics, like cell manipulation and drug delivery. Therefore, a precise and computationally efficient control algorithm for robust trajectory tracking of the 3D printed soft actuators has become important. The results of the primary model of the soft actuator deviated from experimental results due to uncertainties such as time-varying characteristics of the actuator. Hence, a second-order type nonsingular terminal sliding mode controller (NTSMC) for robust stabilization and trajectory tracking of the 3D printed actuator is proposed. It is shown via experiments that…

Bending Control of a 3D Printed Polyelectrolyte Soft Actuator with Uncertain Model

Sensors and Actuators A: Physical 2019

Introduction of 3-dimensional (3D) printing in fabrication and increasing applications of intriguing products in soft robotics have led to studies on controllable 3D printed soft actuators. Therefore, a demand for a precise and computationally efficient model for bending control of the 3D printed soft actuators has arisen. This study initially used a grey box strategy for dynamic modeling of a 3D printed soft actuator which undergoes large bending deformations. Yet, the primary model estimated results deviated from experimental results due to uncertainties such as hysteresis and time varying characteristics of the soft actuator in presence of electric field. Thus, a…

Rigid elements dynamics modeling of a 3D printed soft actuator

Smart Materials and Structures 2019 Volume 28, Issue 2, Article 025003

Due to the growing interest in three-dimensional (3D) printed soft actuators, the establishment of an appropriate mathematical model that could effectively predict the actuators’ dynamic behavior has become necessary. This study presents the development of an effective modeling strategy for the dynamic analysis of a 3D printed polyelectrolyte actuator undergoing large bending deformations. The proposed model is composed of two parts, namely electrical and mechanical dynamic models. The electrical model describes the actuator as a gray box model, whereas the mechanical model relates the stored charges to the bending displacement through considering the printed actuator as a discretized system connected…

3D printed soft parallel actuator

Smart Materials and Structures 2018 Volume 27, Number 4

This paper presents a 3-dimensional (3D) printed soft parallel contactless actuator for the first time. The actuator involves an electro-responsive parallel mechanism made of two segments namely active chain and passive chain both 3D printed. The active chain is attached to the ground from one end and constitutes two actuator links made of responsive hydrogel. The passive chain, on the other hand, is attached to the active chain from one end and consists of two rigid links made of polymer. The actuator links are printed using an extrusion-based 3D-Bioplotter with polyelectrolyte hydrogel as printer ink. The rigid links are also…

Polyelectrolyte Soft Actuators: 3D Printed Chitosan and Cast Gelatin

3D Printing and Additive Manufacturing 2018 Volume 5, Issue 2, Pages 138-150

With increasing utilization of robots in daily tasks, especially in biomedical and environmental monitoring applications, there would be demands for soft, biodegradable, or even edible actuators that provide more versatility than conventional rigid materials (e.g., metals and plastics). Polyelectrolyte hydrogels produce mechanical motion in response to electrical stimulus, making them good candidates for implementation of soft actuators. However, their conventional fabrication process has so far hindered their applicability in a broad range of controlled folding behaviors. A novel application of 3D printing in biodegradable and biocompatible soft robots is presented in this study. It is observed that the contactless electroactive…

Iterative feedback bio-printingderived cell-laden hydrogel scaffolds with optimal geometrical fidelity and cellular controllability

Scientific Reports 2018 Volume 8, Article number: 2802

For three-dimensional bio-printed cell-laden hydrogel tissue constructs, the well-designed internal porous geometry is tailored to obtain the desired structural and cellular properties. However, significant differences often exist between the designed and as-printed scaffolds because of the inherent characteristics of hydrogels and cells. In this study, an iterative feedback bio-printing (IFBP) approach based on optical coherence tomography (OCT) for the fabrication of cell-laden hydrogel scaffolds with optimal geometrical fidelity and cellular controllability was proposed. A custom-made swept-source OCT (SS-OCT) system was applied to characterize the printed scaffolds quantitatively. Based on the obtained empirical linear formula from the first experimental feedback loop,…

Development and Analysis of a 3D Printed Hydrogel Soft Actuator

Sensors and Actuators A 2017 Volume 265, Pages 94–101

Polyelectrolyte hydrogels produce mechanical motion in response to electrical stimulus making them a good candidate for implementation of soft actuators. However, their customary fabrication process has thus far hindered their applicability in a broad range of controlled folding behaviours. This paper employs the 3D printing technology does the development of polyelectrolyte hydrogel soft actuators. A 3D printed soft hydrogel actuator with contactless electrodes is presented for the first time. Initially chitosan as a candidate of polyelectrolytes which possess both printability and stimuli responsive is opted for ink preparation of 3D printing. The printing parameters are optimised for fabrication of desired…

3D Printing of a Photo-thermal Self-folding Actuator

The International Conference on Design and Technology 2017 Pages 15-22

The demand for rapid and accurate fabrication of light-weight, biocompatible, and soft actuators in soft robotics has perused researchers to design and fabricate such products by rapid manufacturing techniques. The self-folding origami structure is a type of soft actuator that has applications in micro electro mechanical systems, soft electronics, and biomedical devices. 3-dimentional (3D) printing is a current manufacturing process that can be used for fabrication of involute soft self-folding products by means of shape memory polymer materials. This paper presents, for the first time, a method for developing a photo thermal self-folding soft actuator using a 3D bioplotter. Easily…