Implantable medical devices (IMDs) are designed to sense specific parameters or stimulate organs and have been actively used for treatment and diagnosis of various diseases. IMDs are used for long-term disease screening or treatments and cannot be considered for short-term applications since patients need to go through a surgery for retrieval of the IMD. Advances in bioresorbable materials has led to the development of transient IMDs that can be resorbed by bodily fluids and disappear after a certain period. These devices are designed to be implanted in the adjacent of the targeted tissue for predetermined times with the aim of measurement of pressure, strain, or temperature, while the bioelectronic devices stimulate certain tissues. They enable opportunities for monitoring and treatment of acute diseases. To realize such transient and miniaturized devices, researchers utilize a variety of materials, novel fabrication methods, and device design strategies. This review discusses potential bioresorbable materials for each component in an IMD followed by programmable degradation and safety standards. Then, common fabrication methods for bioresorbable materials are introduced, along with challenges. The final section provides representative examples of bioresorbable IMDs for various applications with an emphasis on materials, device functionality, and fabrication methods.

A Review of Bioresorbable Implantable Medical Devices: Materials, Fabrication, and Implementation

Highly stable flexible transparent electrode via rapid electrodeposition coating of Ag-Au alloy on copper nanowires for bifunctional electrochromic and supercapacitor device

As one of the most effective surface-enhanced infrared absorption (SEIRA) techniques, metal-insulator-metal structured metamaterial perfect absorbers possess an ultrahigh sensitivity and selectivity in molecular infrared fingerprint detection However, most of the localized electromagnetic fields (ie, hotspots) are confined in the dielectric layer, hindering the interaction between analytes and hotspots By replacing the dielectric layer with the nanofluidic channel, we develop a sapphire (Al2O3)-based mid-infrared (MIR) hybrid nanofluidic-SEIRA (HN-SEIRA) platform for liquid sensors with the aid of a low-temperature interfacial heterogeneous sapphire wafer direct bonding technique The robust atomic bonding interface is confirmed by transmission electron microscope observation We also establish a design methodology for the HN-SEIRA sensor using coupled-mode theory to carry out the loss engineering and experimentally validate its feasibility through the accurate nanogap control Thanks to the capillary force, liquid analytes can be driven into sensing hotspots without external actuation systems Besides, we demonstrate an in situ real-time dynamic monitoring process for the acetone molecular diffusion in deionized water A small concentration change of 029% is distinguished and an ultrahigh sensitivity (08364 pmol-1 %) is achieved With the aid of IR fingerprint absorption, our HN-SEIRA platform brings the selectivity of liquid molecules with similar refractive indexes It also resolves water absorption issues in traditional IR liquid sensors thanks to the sub-nm long light path Considering the wide transparency window of Al2O3 in MIR (up to 52 μm), the HN-SEIRA platform covers more IR absorption range for liquid sensing compared to fused glass commonly used in micro/nanofluidics Leveraging the aforementioned advantages, our work provides insights into developing a MIR real-time liquid sensing platform with intrinsic IR fingerprint selectivity, label-free ultrahigh sensitivity, and ultralow analyte volume, demonstrating a way toward quantitative molecule identification and dynamic analysis for the chemical and biological reaction processes

Nanometer-Scale Heterogeneous Interfacial Sapphire Wafer Bonding for Enabling Plasmonic-Enhanced Nanofluidic Mid-Infrared Spectroscopy

Optomechanical sensing based on the coupling between mechanical motions and optical resonances has attracted huge interest in sensor applications due to its small footprint, high sensitivity, low d...

Progress of optomechanical micro/nano sensors: a review

PurposeEngineering components/structures with geometric discontinuities normally bear complex and variable loads, which lead to a multiaxial and random/variable amplitude stress/strain state. Hence, this study aims how to effectively evaluate the multiaxial random/variable amplitude fatigue life.Design/methodology/approachRecent studies on critical plane method under multiaxial random/variable amplitude loading are reviewed, and the computational framework is clearly presented in this paper.FindingsSome basic concepts and latest achievements in multiaxial random/variable amplitude fatigue analysis are introduced. This review summarizes the research status of four main aspects of multiaxial fatigue under random/variable amplitude loadings, namely multiaxial fatigue criterion, method for critical plane determination, cycle counting method and damage accumulation criterion. Particularly, the latest achievements of multiaxial random/variable amplitude fatigue using critical plane methods are classified and highlighted.Originality/valueThis review attempts to provide references for further research on multiaxial random/variable amplitude fatigue and to promote the development of multiaxial fatigue from experimental research to practical engineering application.

Multiaxial fatigue under variable amplitude loadings: review and solutions

Direct bonding of high dielectric oxides for high-performance transistor applications

Sn–Pb eutectic alloy is widely applied to the deep-space electronics that work under cryogenic environments, but little is known about its responses to the mechanical loading at cryogenic temperatures. In this work, a comprehensive investigation about the deformation and fracture behaviors as well as constitutive relations of the eutectic alloy at cryogenic temperatures was conducted through uniaxial tensile experiments over a full temperature range from 293 K to 77 K, in-situ cryogenic tensile experiments and fractography. With the declining temperature, the tensile strength and quasi-static toughness increase substantially while the elongation is maintained at 25%–30%; Sn–Pb eutectic alloy achieves the optimal combinations of strength, ductility and toughness at 123 K, which is due to a number of deformation twins activated in the Sn matrix together with the compatible deformation between the Pb-rich phases and the Sn matrix. Multiple 45° shear bands induced by the maximum shear stress contribute to reconcile the deformation difference between the two phases, which reaches its minimum at around 123 K. A ductile shear fracture on the 45° shear planes with respect to the tensile axis occurs under the maximum shear stress at temperatures ranging from 293 K to 123 K, while the maximum normal stress leads to a brittle fracture on the 90° planes at 77 K. Moreover, the Anand model fails in fitting the constitutive relations of Sn–Pb eutectic alloy when the temperature declines to 233 K or lower. Instead, the Hollomon equation has been successfully applied to fit the constitutive relations at these invalid temperatures.

Maximum shear stress-controlled uniaxial tensile deformation and fracture mechanisms and constitutive relations of Sn–Pb eutectic alloy at cryogenic temperatures

Xiaoliang Ji

Papers

Direct bonding of high dielectric oxides for high-performance transistor applications

Maximum shear stress-controlled uniaxial tensile deformation and fracture mechanisms and constitutive relations of Sn–Pb eutectic alloy at cryogenic temperatures

Unique buoyancy-force-based kinetics determination of beta to alpha phase transformation in bulk tin plates

Revealing the ductile-to-brittle transition mechanism in polycrystalline body-centered tetragonal tin (Sn) for cryogenic electronics

Robust Cu–Cu Bonding with Multiscale Coralloid Nano-Cu3Sn Paste for High-Power Electronics Packaging