Inkjet printed large-area flexible circuits:a simple methodology for optimizing the printing quality

In this work, a simple methodology was developed to enhance the patterning resolution of inkjet printing, involving process optimization as well as substrate modification and treatment. The line width of the inkjetprinted silver lines was successfully reduced to 1/3 of the original value using this methodology. Large-area flexible circuits with delicate patterns and good morphology were thus fabricated. The resultant flexible circuits showed excellent electrical conductivity as low as 4.5 Ω/□ and strong tolerance to mechanical bending. The simple methodology is also applicable to substrates with various wettability, which suggests a general strategy to enhance the printing quality of inkjet printing for manufacturing high-performance large-area flexible electronics.

Microfibrillated Cellulose Based Ink for Eco-Sustainable Screen Printed Flexible Electrodes in Lithium Ion Batteries

Free organic solvent ink containing graphite, carboxymethyl cellulose and microfibrillated cellulose as active material, dispersing and binder, respectively, has been formulated to produce flexible and eco- sustainable electrodes for lithium ion batteries. Content ratio of components and dispersion protocol were tailored in order to have theological properties suitable for a large and cheap manufacturing process as well as screen printing. The bio-sourced printed electrodes exhibit a high porosity value of 70% that limits the electrochemical performances. However, the calendering process enhances electrode performances by increasing the reversible capacity from 85 until 315 mAh/g and reducing porosity to an optimal value of 34%. Moreover the introduction of 2% w/w of monofluoro-ethylene carbonate in the electrolyte reduced their reversible capacity loss of 11% in the printed electrode.

Interfacial engineering of printable bottom back metal electrodes for full-solution processed flexible organic solar cells

Printing of metal bottom back electrodes of flexible organic solar cells（FOSCs） at low temperature is of great significance to realize the full-solution fabrication technology. However, this has been difficult to achieve because often the interfacial properties of those printed electrodes, including conductivity, roughness, work function,optical and mechanical flexibility, cannot meet the device requirement at the same time. In this work, we fabricate printed Ag and Cu bottom back cathodes by a low-temperature solution technique named polymer-assisted metal deposition（PAMD） on flexible PET substrates. Branched polyethylenimine（PEI） and ZnO thin films are used as the interface modification layers（IMLs） of these cathodes. Detailed experimental studies on the electrical, mechanical, and morphological properties, and simulation study on the optical properties of these IMLs are carried out to understand and optimize the interface of printed cathodes. We demonstrate that the highest power conversion efficiency over 3.0% can be achieved from a full-solution processed OFSC with the device structure being PAMDAg/PEI/P3 HT：PC61BM/PH1000. This device also acquires remarkable stability upon repeating bending tests.

Pencil painting like preparation for flexible thermoelectric material of high-performance p-type Na_(1.4)Co_(2)O_(4) and novel n-type NaxCo_(2)O_(4)

Flexible thermoelectric materials are presented with potential applications in electronic devices and energy conversion due to their convenient preparation,good flexibility,and various forms.However,as ductility is rarely observed in inorganic semiconductors and ceramic insulators,reports on applications of inorganic oxide materials in flexible thermoelectric materials are sparse.Here,we report a new method for the synthesis of a flexible Na_(1.4)Co_(2)O_(4) thermoelectric material based on Na_(1.4)Co_(2)O_(4) bulk materials,which are prepared by a self-flux method and painted on print paper.Seebeck coefficient and power factor of the obtained thermoelectric material are 78-102 μVK^(-1) and 159e223 mWm^-(1)K^(-2),respectively,in a temperature range of 303-522 K,which are superior to those values of other conductive polymers and their compounds.More interestingly,the n-type Na_(1.4)Co_(2)O_(4) flexible material is obtained in the painting process at higher pressure with Seebeck coefficients of109 to183 μVK^(-1) in a temperature range of 303-522 K.The convenient preparation method of these novel flexible thermoelectric materials may be expanded to the synthesis of other flexible thermoelectric materials,which will be the focus of future work.

FPC-BTB detection and positioning system based on optimized YOLOv5

With the aim of addressing the visual positioning problem of board-to-board(BTB)jacks during the automatic assembly of flexible printed circuit(FPC)in mobile phones,an FPC-BTB jack detection method based on the optimized You Only Look Once,version 5(YOLOv5)deep learning algorithm was proposed in this study.An FPC-BTB jack real-time detection and positioning system was developed for the real-time target detection and pose output synchronization of the BTB jack.On that basis,a visual positioning experimental platform that integrated a UR5e manipulator arm and Hikvision industrial camera was built for BTB jack detection and positioning experiments.As indicated by the experimental results,the developed FPC-BTB jack detection and positioning system for BTB target recognition and positioning achieved a success rate of 99.677%.Its average detection accuracy reached 99.341%,the average confidence of the detected target was 91%,the detection and positioning speed reached 31.25 frames per second,and the positioning deviation was less than 0.93 mm,which conforms to the practical application requirements of the FPC assembly process.

Material,design,and fabrication of custom prosthetic liners for lower-extremity amputees:A review

As a physical interface,a prosthetic liner is commonly used as a transition material between the residual limb and the stiff socket.Typically made from a compliant material such as silicone,the main function of a prosthetic liner is to protect the residual limb from injuries induced by load-bearing normal and shear stresses.Compared to conventional liners,custom prosthetic lower-extremity(LE)liners have been shown to better relieve stress concentrations in painful and sensitive regions of the residual limb.Although custom LE liners have been shown to offer clinical benefits,no review article on their design and efficacy has yet been written.To address this shortcoming in the literature,this paper provides a comprehensive survey of custom LE liner materials,design,and fabrication methods.First,custom LE liner materials and components are summarized,including a description of commercial liners and their efficacy.Subsequently,digital methods used to design and fabricate custom LE liners are addressed,including residual limb biomechanical modeling,finite element-based design methods,and 3-D printing techniques.Finally,current evaluation methods of custom/commercial LE liners are presented and discussed.We hope that this review article will inspire further research and development into the design and manufacture of custom LE liners.