In an effort to contribute to the ongoing development of ASTM standards for additively manufactured metal lattice specimens, particularly within the field of medicine, the compressive and tensile mechanical properties of biomimetic lattice structures produced by laser powder bed fusion (L-PBF) using Ti-6Al-4V feedstock powder were investigated in this research. The geometries and porosities of the lattice structures were designed to facilitate internal bone growth and prevent stress shielding. A thin strut thickness of 200 µm is utilized for these lattices to mimic human cancellous bone. In addition to a thin strut size, two different strut geometries were utilized (cubic and body-centered cubic), along with four different pore sizes (400, 500, 600, and 900 µm, representing 40–90% porosity in a 10 mm cube). A 10 mm³ cube was used for compression testing and an experimental pin-loaded design was implemented for tensile testing. The failure mode for each specimen was examined using scanning electron microscopy (SEM). Lattice structures were compared to the mechanical properties of human cancellous bone. It was found that the elastic modulus of human cancellous bone (10–900 MPa) could be matched for both the tensile (92.7–129.6 MPa) and compressive (185.2–996.1 MPa) elastic modulus of cubic and body-centered cubic lattices. Body-centered cubic lattices exhibited higher compressive properties over cubic, whereas cubic lattices exhibited superior tensile properties. The experimental tensile specimen showed reacquiring failures close to the grips, indicating that a different tensile design may be required for consistent data acquisition in the future.

Wearable electronics are playing an important role in the health care industry. Wearable sensors are either directly attached to the body surface or embedded into worn garments. Textile-based batteries can help towards development of body conformal wearable sensors. In this letter, we demonstrate a 2D planar textile-based primary Ag₂O–Zn battery fabricated using the stencil printing method. A synthetic polyester woven fabric is used as the textile substrate and polyethylene oxide material is used as the separator. The demonstrated battery achieves an areal capacity of 0.6 mAh/cm² with an active electrode area of 0.5 cm × 1 cm.

Flexible power sources such as batteries are essential to realize wearable and conformable electronic devices. The mechanical stability of the electrodes plays an important role in determining the overall flexibility of the battery. Styrene block copolymers-based elastomers have the potential to be used as binder materials in the electrodes for retaining their structural integrity under flexing during regular use. In this work, we demonstrate a stencil-printed flexible primary Ag₂O-Zn battery on a nonconductive nylon mesh substrate that uses styrene-butadiene rubber as the anodic binder. A polyacrylic acid-based alkaline polymer gel is used as an electrolyte. The flexible alkaline battery achieved discharge capacities of $2.5 \mathrm{mAh}$ and $1.6 \mathrm{mAh}$ without and with a bend radius of 0.8 $\mathrm{cm}$, respectively, under a constant current load condition of $0.1 \mathrm{mA}$.

Lattice structures have demonstrated the ability to provide secondary stability in orthopedic implants by promoting internal bone growth. In response to the growing prevalence of lattices in orthopedic design, we investigated the effects of porosity and unit cell geometry in additively manufactured Ti-6Al-4V biomimetic lattice structures on the osteogenesis of human MG-63 osteoblastic cell lines in vitro. We analyzed glucose consumption, alkaline phosphatase (ALP) concentration, and end-of-culture cell count as markers for osteogenic growth. Two different strut geometries were utilized (cubic and body-centered cubic), along with four different pore sizes (400, 500, 600, and 900 µm, representing 40–90% porosity in a 10 mm cube), in addition to a solid specimen. Structural characterization was performed using scanning electron microscopy. The results indicated that lattices with a 900 µm pore size exhibited the highest glucose consumption, the greatest change in ALP activity, and the highest cell count when compared to other pore sizes. Cubic 900 µm lattice structures outperformed other specimens in facilitating the maturation of viable MG-63 cells from the formation to the mineralization phase of bone remodeling, offering the most promise for osseointegration in additively manufactured titanium implants in the future. However, irrespective of a particular pore size or unit cell geometry, it was found that all the lattices were capable of promoting osteogenic growth due to surface roughness in the printed parts.

Printed textile-based flexible batteries are gaining attention in several applications, but they are becoming more relevant to the health care industry in terms of realizing wearable and skin-conformable electronic devices. A flexible battery must ideally be deformable along multiple directions. In this work, with an aim to develop a fully printed omnidirectional deformable battery, we report the fabrication process of a novel single-polymer-based flexible non-rechargeable planar Ag₂O-Zn battery on a textile substrate using the stencil printing method. Except for the electrolyte, all the components of the battery, including the current collectors, the anode, the cathode, and the separator membrane, are fabricated using a single polymer, namely styrene–ethylene–butylene–styrene (SEBS). To fabricate the SEBS separator, we introduce the solvent evaporation-induced phase separation (SEIPS) process. In the SEIPS method, toluene and dimethyl sulfoxide (DMSO) are selected as the solvent–nonsolvent pair. The SEBS: toluene: DMSO system with a wt% ratio of 6:85:9 showed improved performance regarding the OCV tests. A polyacrylic acid (PAA)-based alkaline polymer gel is used as an electrolyte. The demonstrated process is simple, and, with suitable modifications, it should find its use in the development of digitally printed alkaline batteries.