Insulin pumps have transformed the way diabetes is managed by providing a more accurate and individualized method of delivering insulin, in contrast to conventional injection routines. This research explores the progression of insulin pumps, following their advancement from initial ideas to advanced contemporary systems. The report proceeds to categorize insulin pumps according to their delivery systems, specifically differentiating between conventional, patch, and implantable pumps. Every category is thoroughly examined, emphasizing its unique characteristics and capabilities. A comparative examination of commercially available pumps is provided to enhance informed decision making. This section provides a thorough analysis of important specifications among various brands and models. Considered factors include basal rate and bolus dosage capabilities, reservoir size, user interface, and compatibility with other diabetes care tools, such as continuous glucose monitoring (CGM) devices and so on. This review seeks to empower healthcare professionals and patients with the essential information to improve diabetes treatment via individualized pump therapy options. It provides a complete assessment of the development, categorization, and full specification comparisons of insulin pumps.

This paper reports numerical studies of an Elasto-Hydrodynamic (EHD) seal, which is being developed for supercritical CO₂ (sCO₂) turbomachinery applications. Current sCO₂ turbomachinery suffers from high leakage rates, which is creating a major roadblock to the full realization of sCO₂ power technology. The high leakage rates not only penalize the efficiencies but also create environmental concerns due to greenhouse effects caused by the increased CO₂ discharge to the atmosphere. The proposed EHD seal needs to work at elevated pressures (10–35 MPa) and temperatures (350–700 °C) with low leakage and minimal wear. The unique mechanism of the EHD seal provides a self-regulated constriction effect to restrict the flow without substantial material contact, thereby minimizing leakage and wear. This work utilizes a physics-based modeling approach. The flow through the gradually narrowing seal clearance is modeled by the well-known Reynolds equation in EHD lubrication theory, while the deformation of the seal is modeled by using the governing equations of three-dimensional solid mechanics. As for the solution methodology, COMSOL’s Thin-Film Flow and Solid Mechanics modules were employed with their powerful capabilities. The numerical results were presented and discussed. It was observed that the Reynolds equation fully coupled with the surface deformation was able to successfully capture the constriction effect. The maximum and minimum leakages were calculated to be 2.25 g/s and 0.1 g/s at P = 5.5 MPa and P = 11 MPa for the design seal, respectively. It was interesting to observe that the seal leakage followed a quadratic trend with increasing pressure differential, which can become advantageous for high-pressure applications such as sCO₂ power generation technology.

Effective sealing is a critical challenge in achieving the full potential of supercritical carbon dioxide (sCO₂) power generation. Leakages from sCO₂ cycles can reduce efficiency by up to 0.65%, underscoring the need for advanced sealing solutions. This study explores an elastohydrodynamic (EHD) seal as a promising option, designed to minimize leakage and wear under sCO₂ conditions. A fluid-solid coupling model, based on finite element analysis and computational fluid dynamics, was developed and experimentally validated. Proof-of-concept tests were conducted on a 2-inch static shaft seal with pressures up to 1.2 MPa, using PTFE as the seal material. Both simulations and experiments revealed a quadratic leakage trend: leakage initially increased with pressure, peaked at about 6 g/s, and then declined to approximately 1.5 g/s at maximum pressure. The model proved efficient, converging in just 2 seconds, while providing insights into leakage rates, seal deformation, clearance pressure, and stress. In addition, a modified model was provided, which converged in less than 20 seconds with added accuracy. A parametric analysis further demonstrated the impact of key design factors on leakage, with results aligning with physical expectations. The proposed models could serve as a valuable design tool for EHD seals.