Functioning ingestible capsules offer tremendous promise for a plethora of diagnostic and therapeutic applications. However, the absence of realistic and practical power solutions has greatly hindered the development of ingestible electronics. Microbial fuel cells (MFCs) hold great potential as power sources for such devices as the small intestinal environment maintains a steady internal temperature and a neutral pH. Those conditions and the constant supply of nutrient-rich organics are a perfect environment to generate long-lasting power. Although previous small-scale MFCs have demonstrated many promising applications, little is known about the potential for generating power in the human gut environment. Here, this work reports the design and operation of a microbial biobattery capsule for ingestible applications. Dormant Bacillus subtilis endospores are a storable anodic biocatalyst that will provide on-demand power when revived by nutrient-rich intestinal fluids. A conductive, porous, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate hydrogel anode enables superior electrical performance in what is the world's smallest MFC. Moreover, an oxygen-rich cathode maintains its effective cathodic capability even in the oxygen-deficit intestinal environment. As a proof-of-concept demonstration in stimulated intestinal fluid, the biobattery capsule produces a current density of 470 µA cm⁻² and a power density of 98 µW cm⁻², ensuring its practical efficacy as a novel and sole power source for ingestible applications in the small intestine.

中文翻译：

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用于小肠中可摄入电子产品的生物电池胶囊：从肠液中产生生物能量激活外生电细菌内生孢子的萌发

功能性可摄入胶囊为大量的诊断和治疗应用提供了巨大的希望。然而，缺乏切合实际的电源解决方案极大地阻碍了可摄入电子产品的发展。微生物燃料电池 (MFC) 作为此类设备的电源具有巨大潜力，因为小肠环境可保持稳定的内部温度和中性 pH 值。这些条件和富含营养的有机物的持续供应是产生持久电力的完美环境。尽管之前的小型 MFC 已经展示了许多有前途的应用，但人们对在人体肠道环境中发电的潜力知之甚少。在这里，这项工作报告了用于可摄取应用的微生物生物电池胶囊的设计和操作。休眠枯草芽孢杆菌内生孢子是一种可储存的阳极生物催化剂，当被富含营养的肠液恢复时，它将提供按需提供的能量。导电多孔聚（3,4-亚乙基二氧噻吩）聚苯乙烯磺酸盐水凝胶阳极可在世界上最小的 MFC 中实现卓越的电气性能。此外，富氧阴极即使在缺氧的肠道环境中也能保持其有效的阴极能力。作为刺激肠液的概念验证演示，生物电池胶囊产生 470 µA cm ^-2的电流密度和 98 µW cm ^-2的功率密度，确保其作为可摄取的新型和唯一电源的实用功效在小肠中的应用。