Recent developments in flexible printed heaters (FPHs) for wearable thermal applications, driven by the advancement of printed electronics, show great promise in revolutionizing patient care through the development of wearable flexible heaters for medical applications. Wearable heaters with high thermal stability, heat uniformity, safety, flexibility, comfort, biocompatibility, biodegradability, recyclability, and power efficiency are desirable for standalone medical thermotherapy applications. This paper reviews recent advancements in the design of FPHs for wearable thermal applications. Materials used in the FPHs, fabrication methods, design considerations, temperature control mechanisms, medical applications, and performance analysis of specific FPHs are all thoroughly discussed. Materials used in FPHs, such as conductive and substrate materials, receive special attention along with the heater design parameters. Additionally, the paper addresses the challenges and future directions for the advancement of FPHs in wearable medical applications.

The integration of electronics into textiles has gained considerable attention in recent years, due to the development and high demand of wearable and flexible electronics. One of the promising fields is healthcare, which often involves the utilization of textile-based electrodes. These electrodes often offer advantages such as conformability, breathability, and comfort. This article presents the development of 3D-formed textile-based electrodes together with a narrow fabric-based interconnect system. This study showcases the methods and materials for the fabrication of the textile-based electrodes and the interconnect system, including a durability assessment, by performing standardized washing (ISO 6330-2012) and user tests. The results demonstrated that the developed 3D-formed textile-based electrodes and stretchable interconnect system are durable and effective for wearable applications, maintaining performance under extensive washing.

Recent developments in flexible printed heaters (FPH) for wearable thermal applications, driven by the advancement of printed electronics, show great promise in revolutionizing patient care through the development of wearable flexible heaters for medical applications. Wearable heaters with high thermal stability, heat uniformity, safety, flexibility, comfort, biocompatibility, and power efficiency are desirable for stand-alone medical thermotherapy applications. This paper reviews recent advancements in the design of FPHs for wearable thermal applications. Materials for FPHs, fabrication methods, designs, temperature control mechanisms, medical applications, and performance analysis of specific FPHs are all thoroughly discussed. Materials for FPHs, such as conductive and substrate materials, have received special attention, along with the heater design parameters. Finally, the challenges and future directions for developing FPHs for wearable medical applications are addressed.

In a monolithically integrated GaN-IC, the parasitic inductance, capacitance and resistance between the driver and the half-bridge is greatly reduced. In a GaN-IC platform on SOI combined with oxide filled deep trench isolation, the back-gating effect on the high-side power device is eliminated. Yet some issues related to the epitaxial stack and the substrate contact layer need to be addressed. In this paper, a substrate network concept is presented for 200V p-GaN gate HEMTs on SOI, and the impact of the epitaxial stack on device operation is investigated through modeling the epitaxial stack as a parallel R-C network. Double pulse tests were simulated and the impact on the substrate current was investigated. It is concluded that the substrate current peaks have a strong dependency on the epitaxial stack and the switching times, and that the peaks can be reduced by increasing the substrate layer resistivity.

Experimental data from gallium nitride (GaN)-on-Si p-GaN gate high-electron-mobility transistors (HEMTs) reveal a strong dependence of terminal capacitances-particularly $C_{\mathrm{BS}}, C_{\mathrm{BG}}$ , and $C_{\mathrm{BD}}$ -on the drain-to-source voltage ( $V_{\mathrm{DS}}$ ), indicating significant coupling through the bulk contact. This behavior, linked to progressive depletion of the 2-D electron gas (2DEG) under field plates, is not adequately captured by existing compact models. This work presents a detailed analysis of the dynamics of $V_{\text {DS }}$ -dependent depletion under field plates and develops an enhanced MIT Virtual Source GaN FET (MVSG) compact model that incorporates bulk-related capacitance contributions. The proposed model introduces a depletion-dependent modulation of channel and fringing capacitances and captures channel length modulation (CLM) effects due to progressive depletion of 2DEG with increasing $V_{\text {DS }}$ . The extended model shows excellent agreement with the measured capacitance behavior and provides a deeper understanding of the substrate interaction mechanisms. This advancement supports the design of next-generation high-voltage GaN power ICs, such as integrated half-bridges and gate drivers, by enabling accurate prediction of terminal capacitances in simulations that include substrate effects.

Background/Objectives: Neonatal hypothermia remains a significant contributor to neonatal mortality and morbidity mainly in low and middle-income countries, such as those in sub-Saharan Africa. The objective of this systematic review and meta-analysis is to assess the prevalence of neonatal hypothermia and its risk factors in sub-Saharan Africa. Methods: The Preferred Reporting Items for Systematic Review and Meta-Analysis statement (PRISMA) guideline was used to search databases (PubMed, Scopus, Cocrane library and Google Scholar) for studies reporting both the prevalence and factors associated with neonatal hypothermia in sub-Saharan Africa. We have included cross-sectional, cohort and descriptive studies published between 1 June 2014 and 31 May 2024. The Joanna Briggs Institute (JBI) quality appraisal checklist was used for the appraisal of studies. Subgroup analysis was conducted by country, study design and population. A total of 21 articles with 12,803 participants from 9 countries were included in the analysis. Results: The pooled prevalence of neonatal hypothermia was 55.39% (95% CI: 48.52, 62.25). Preterm birth (odds ratio (OR): 3.49; 95% CI: 1.98–6.16), low birth weight (OR: 3.56; 95% CI: 2.36–5.39), no skin-to-skin contact (OR: 1.31; 95% CI: 0.55–3.13), lack of resuscitation (OR: 2.56; 95% CI: 1.75–3.76), delayed initiation of breast feeding (OR: 2.38; 95% CI: 1.57–3.61), admission during cold season (OR: 1.80; 95% CI: 1.33–2.44), home delivery (OR: 1.94; 95% CI: 1.51–2.50) and early bathing (OR: 3.03; 95% CI: 0.98–9.38) were the factors significantly associated with neonatal hypothermia. Conclusions: The observed high prevalence of hypothermia was associated with physiological, behavioral and environmental factors.