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1. TRANSIENT BIOBATTERIES: MICROFLUIDIC CONTROL FOR PROGRAMMABLE DISSOLUTION

   https://doi.org/10.31438/trf.hh2018.48  

   Mohammadifar, M.; Choi, S. (January 2019, 2018 Solid-State Sensors, Actuators and Microsystems Workshop)

   We report a simple approach to develop transient microbial fuel cells with the capability of dissolving in water after stable power generation within a programmed period. This novel watersoluble biobattery makes use of the integration of a dissolvable paper-based substrate, a simple pencil-drawn graphite anode, and a Prussian-blue (PB) cathode. The device features (i) a low cost transient paper-based platform, (ii) easily accessible electrode materials and simple fabrication steps and (iii) a time-controlled operation by using the number of serpentine microfluidic channels. The biobatteries reached to a maximum power of 0.5μW and a current 15.6μA 

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2. A Transient Spore‐Forming Microbial Fuel Cell with Extracellularly Biosynthesized Tin Oxide Nanoparticles for Powering Disposable and Green Papertronics

   https://doi.org/10.1002/adsu.202300357  

   Rezaie, Maryam; Rafiee, Zahra; Choi, Seokheun (October 2023, Advanced Sustainable Systems)

   Abstract Transient electronics, which can operate only for short‐lived applications and then be eco‐friendly disintegrated, create opportunities in environmental sensing, healthcare, and hardware security. Paper‐based electronics, or papertronics, recently have rapidly advanced the physically transient device platform because paper as a foundation offers an environmentally sustainable and cost‐effective option for those increasingly pervasive and fast‐updated single‐use applications. Paper‐based power supplies are indispensable to realize a fully papertronic paradigm and are a critical enabler of environmentally benign power solutions. Microbial fuel cells (MFCs) hold great potential as power sources for such green papertronic applications. This work reports the design, operation, and optimization of a high‐power papertronic MFC by biosynthesizing microbe‐mediated tin oxide nanoparticles (SnO₂NPs) on dormant Bacillus subtilis endospores. They form an electrical conduit that improves electron harvesting during the spore germination and power generation. The MFC is packaged in a sub‐microporous alginate to minimize the potential risk of bacteria leakage. Upon the introduction of water, the paper‐based MFC generates a significantly enhanced power density of 140 µW cm⁻², which is more than two orders of magnitude greater than their previously reported counterparts. Six MFCs connected in series generate more than sufficient power to run an on‐chip, light‐emitting diode. 

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3. Probabilistic Transient Stability Assessment of Power System Considering Wind Power Uncertainties and Correlations

   Yue, Ziyuan; Liu, Yanli; Yu, Yixin; Zhao, Junbo (January 2020, International journal of power energy systems)

   This paper proposes a simple yet effective method for power system probabilistic transient stability assessment considering the wind farm uncertainties and correlations. Specifically, the inverse Nataf-transformation-based three-point estimation method and the Cornish-Fisher expansion have been integrated together to deal with the uncertainties and the correlations among different wind farms. Then, by resorting to the extended dynamic security region approach, the transient stability criterion is derived as a linear combination of nodal injection vector under a given fault condition. New indices for the identification of critical lines have also been developed. Extensive simulation results carried out on four different systems, including the practical GZ power system in China show that the computational efficiency of the proposed method is much higher than the Monte-Carlo-based method and other methods almost without the loss of accuracy. The effectiveness of the proposed method under different penetrations of wind power with different degree of correlations is also validated. It is shown that correlation among wind farms has a larger impact on the transient stability results with a higher penetration level of renewable energy. 

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4. Transient behaviour verification and controller tuning for an uncertain grid‐connected photovoltaic system using reachability analysis

   https://doi.org/10.1049/rpg2.12212  

   Shabestari, Parisa_M; Mehrizi‐Sani, Ali (May 2021, IET Renewable Power Generation)

   Abstract Power electronics–based converters for photovoltaic (PV) systems are susceptible to overcurrents; it is important to design their controllers to reduce the transient current for all viable operating conditions. To design a current controller and find the maximum transient current via simulation‐based techniques, the exact values of the system parameters, initial states, and inputs are required. However, they are not precisely known in practice, some system parameters such as inductances may change over time, and output power and load are variable. The uncertainty in the parameter (filter inductance) and input of the system (injected power) should be considered in the analysis of a PV system controllers as it can degrade their performance, which are designed for the system nominal parameters. This paper employs reachability analysis for a grid‐connected PV system to (1) find the maximum transient current, (2) devise an improved PI current controller and (3) compare the maximum transient current in PI‐ and internal model control (IMC)‐based controllers with uncertain‐but‐bounded input power and inductance error. Simulation and experimental studies showcase the results. 

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5. Dissolvable Probiotic‐Powered Biobatteries: A Safe and Biocompatible Energy Solution for Transient Applications

   https://doi.org/10.1002/smll.202502633  

   Rezaie, Maryam; Mohammadifar, Maedeh; Choi, Seokheun (March 2025, Small)

   Abstract For decades, science fiction has imagined electronic devices that spring to life on demand, function as programmed, and then vanish without a trace. Today, transient and bioresorbable electronics are making that vision a reality, sparking revolutionary progress in biomedicine, environmental stewardship, and hardware security. Yet one critical barrier remains: a fully transient power source with the same disappearing act. Microbial‐based biobatteries have emerged as strong contenders, harnessing the power of microorganisms—found virtually everywhere—as natural biocatalysts. However, toxicity and health risks have limited these systems to single‐use, often incinerable applications. Here, a transformative approach: a transient biobattery powered by commercially available probiotics that dissolves harmlessly is introduced, releasing only beneficial microbes. Fabricated on water‐soluble or pH‐responsive substrates, this biobattery capitalizes on a 15‐strain probiotic blend to generate electricity across diverse electrode materials. By manipulating device length or encapsulating it with pH‐sensitive polymers, power delivery can be fine‐tuned from 4 min up to over 100 min. A single module outputs 4 µW of power, 47 µA of current, and an open‐circuit voltage of 0.65 V. This groundbreaking design ushers in a new era of safe, effective transient bioenergy systems, opening unprecedented opportunities in biomedical implants, environmental sensors, and disposable electronics. 

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