The advent of personalized wearable devices has boosted the demand for portable, compact power sources. Compared with lithographic techniques, printed devices have lower fabrication costs, while still maintaining high throughput and precision. These factors make thick film printing or additive manufacturing ideal for the fabrication of low-cost batteries suitable for personalized devices. This article provides comprehensive guidelines for thick-film battery fabrication and characterization, with the focus on printed nickel-zinc (Ni-Zn) batteries. Ni-Zn batteries are a more environmental-friendly option compared with lithium-ion batteries (LIBs) as they are fully recyclable. In this work, important battery fundamentals have been described, especially terms of electrochemistry, basic design approaches, and the printing technology. Different design approaches, such as lateral, concentric, and stacked, are also discussed. Printed batteries can be configured as series or parallel constructions, depending on the power requirements of the application. The fabrication flow of printed battery electrodes for the laboratory-scale prototyping process starts from chemical preparation, mixing, printing, drying, pressing, stacking to finally sealing and testing. Of particular importance is the process of electrolyte injection and pouch sealing for the printed batteries to reduce leakage. This entire process flow is also compared with industrial fabrication flow for LIBs. Criteria for material and equipment selection are also addressed in this article to ensure appropriate electrode consistency and good performance. Two main testing methods cyclic voltammetry for the electrodes and charge-discharge for the battery are also explained in detail to serve as systematic guide for users to validate the functionality of their electrodes. This review article concludes with commercial applications of printed electrodes in the field of health and personalized wearable devices. This work indicates that printed Ni-Zn and other zinc alkaline batteries have a promising future. The success of these devices also opens up different areas of research, such as ink rheology, composition, and formulation of ink using sustainable sources.
Fused deposition modeling has provided a cheap and effective method for the rapid production of prototypes and functional products in many spheres of life. In this study, three-dimensional (3D) printing techniques to produce and optimize a hip protector that will assure clinical efficacy are presented. The I-Optimal design was used to optimize the hip protector's significant parameters (infill density, shell thickness, and material shore hardness) to obtain maximum femoral neck force attenuation of the 3D-printed hip protector. A drop impact tower device simulates the impact force at the hip's parasagittal plane during a fall. The results show that the infill density has the most significant influence on attenuation properties, followed by the infill density combined with the material shore hardness. By maximizing all the parameters, it is demonstrated that using an additive manufacturing technique to print hip protectors could be an effective strategy in curbing hip fractures.
This research concerns on the application of combined thermomechanical-inherent strain method (TMM-ISM) in predicting the distortion of additively manufactured component. The simulation and experimental verification were conducted in the form of vertical cylinder using selective laser melting, which was subsequently cut in the middle section. The setup and procedure of simulation approaches followed the actual process parameters such as laser power, layer thickness, scan strategy, and temperature dependent material, including flow curve retrieved from specialized computational numerical software. The investigation began with virtual calibration test using TMM, followed by manufacturing process simulation using ISM. Based on the maximum deformation result of simulated calibration and accuracy consideration from previous equivalent study, the inherent strain values used in ISM analysis were obtained using self-developed optimization algorithm with direct pattern search Nelder-Mead method in finding the minimum error of distortion using MATLAB. The error minima were measured between transient TMM-based simulation and simplified formulation in calculating the inherent strain values with respect to longitudinal and transverse laser directions. Furthermore, the combined TMM-ISM distortion results were compared to fully TMM with equivalent mesh number and verified based on experimental investigation conducted by renowned researcher. It can be concluded that the result of slit distortion from TMM-ISM and TMM showed good agreement with the error percentage of 9.5% and 3.5%, respectively. However, the computational time for combined TMM-ISM was reduced tremendously with only 63 min if compared to TMM with 129 min in running full simulation on solid cylindrical component. Hence, combined TMM-ISM-based simulation can be considered as an alternative method to replace time-consuming and cost-intensive calibration preparation and analysis.