可植入电池可利用人体自身的氧气运行

From pacemakers to neurostimulators, implantable medical devices rely on batteries to keep the heart on beat and dampen pain. But batteries eventually run low and require invasive surgeries to replace. To address these challenges, researchers in China devised an implantable battery that runs on oxygen in the body. The study, published March 27 in the journal Chem, shows in rats that the proof-of-concept design can deliver stable power and is compatible with the biological system.
从心脏起搏器到神经刺激器，植入式医疗设备依赖电池维持心跳和缓解疼痛。但电池终会耗尽，需通过侵入性手术更换。为解决这些难题，中国研究人员设计出一种利用体内氧气驱动的植入式电池。3月27日发表在《Chem》期刊的研究表明，这一概念验证设计能在大鼠体内提供稳定电力，且与生物系统兼容。

"When you think about it, oxygen is the source of our life," says corresponding author Xizheng Liu, who specializes in energy materials and devices at Tianjin University of Technology. "If we can leverage the continuous supply of oxygen in the body, battery life won't be limited by the finite materials within conventional batteries."
"仔细想想，氧气是我们生命的源泉，"通讯作者、天津理工大学能源材料与器件专家刘喜正（Xizheng Liu）表示，"如果我们能利用体内持续供应的氧气，电池寿命就不会受到传统电池有限材料的限制。"

To build a safe and efficient battery, the researchers made its electrodes out of a sodium-based alloy and nanoporous gold, a material with pores thousands of times smaller than a hair's width. Gold has been known for its compatibility with living systems, and sodium is an essential and ubiquitous element in the human body. The electrodes undergo chemical reactions with oxygen in the body to produce electricity. To protect the battery, the researchers encased it within a porous polymer film that is soft and flexible.
为了制造安全高效的电池，研究人员采用钠基合金和纳米多孔金（孔隙比发丝直径小数千倍的材料）制作电极。金因其与生命系统的兼容性而闻名，钠则是人体内无处不在的重要元素。这些电极通过与体内氧气发生化学反应来发电。为保护电池，研究人员将其封装在柔软多孔的高分子聚合物薄膜内。

The researchers then implanted the battery under the skin on the backs of rats and measured its electricity output. Two weeks later, they found that the battery can produce stable voltages between 1.3 V and 1.4 V, with a maximum power density of 2.6 µW/cm². Although the output is insufficient to power medical devices, the design shows that harnessing oxygen in the body for energy is possible.
研究人员随后将电池植入大鼠背部皮下并测量其电力输出。两周后，他们发现该电池可产生1.3V至1.4V的稳定电压，最大功率密度达2.6µW/cm²。虽然这一输出不足以驱动医疗设备，但该设计证明利用体内氧气获取能量是可行的。

The team also evaluated inflammatory reactions, metabolic changes, and tissue regeneration around the battery. The rats showed no apparent inflammation. Byproducts from the battery's chemical reactions, including sodium ions, hydroxide ions, and low levels of hydrogen peroxide, were easily metabolized by the body and did not affect the kidneys and liver. The rats healed well after implantation, with the hair on their back completely regrown after four weeks. To the researchers' surprise, blood vessels also regenerated around the battery.
该团队还评估了电池周围的炎症反应、代谢变化和组织再生情况。大鼠未出现明显炎症。电池化学反应产生的副产物（包括钠离子、氢氧根离子和低浓度过氧化氢）可被机体轻松代谢，且未影响肾脏和肝脏。大鼠在植入后恢复良好，四周后背部毛发完全再生。令研究人员惊讶的是，电池周围还出现了血管再生现象。

"We were puzzled by the unstable electricity output right after implantation," says Liu. "It turned out we had to give the wound time to heal, for blood vessels to regenerate around the battery and supply oxygen, before the battery could provide stable electricity. This is a surprising and interesting finding because it means that the battery can help monitor wound healing."
刘说："植入后电力输出不稳定让我们很解谜。结果发现，我们需要给伤口时间愈合，让血管在电池周围再生并供应氧气，之后电池才能提供稳定的电力。这是一个令人惊讶且有趣的发现，因为这意味着电池可以帮助监测伤口愈合。"

Next, the team plans to up the battery's energy delivery by exploring more efficient materials for the electrodes and optimizing the battery structure and design. Liu also noted that the battery is easy to scale up in production and choosing cost-effective materials can further lower the price. The team's battery may also find other purposes beyond powering medical devices.
接下来，该团队计划通过探索更高效的电极材料和优化电池结构与设计，提高电池的能量输出。Liu还指出，这种电池易于扩大生产规模，选用性价比高的材料可进一步降低价格。该团队研发的电池除为医疗设备供电外，还可能找到其他用途。

"Because tumor cells are sensitive to oxygen levels, implanting this oxygen-consuming battery around it may help starve cancers. It's also possible to convert the battery energy to heat to kill cancer cells," says Liu. "From a new energy source to potential biotherapies, the prospects for this battery are exciting."
"由于肿瘤细胞对氧气水平敏感，在其周围植入这种耗氧电池可能有助于饿死癌细胞。还可以将电池能量转化为热量来杀死癌细胞，"刘说。"从新能源到潜在的生物疗法，这种电池的前景令人兴奋。"