DEVICES THAT peer(窥视、端详) into the human body from the outside, like X-ray scanners and MRI machines, have transformed medicine. A new generation of ingestible(可吞服的) sensors could do the same from the inside. But these require power, and as standard batteries contain harmful chemicals, swallowing them is generally inadvisable.(但它们需要电力，而标准电池含有有害化学物质，吞下去通常并不可取。)
X光扫描仪、核磁共振仪这类从体外窥探人体的设备，已经彻底改变了医学。新一代可吞服传感器则有望从体内实现同样的变革。但它们需要电力，而标准电池含有有害化学物质，吞下去通常并不可取。
To get around this problem, ingestible sensors—most commonly small, pill-like cameras—are often designed so their batteries do not contact the body and the entire unit is eventually excreted.(为解决这一难题，可吞服传感器——最常见的是药丸大小的小型摄像头——通常被设计成电池不接触人体，整个装置最终随粪便排出。) Sometimes their protective casing(外壳、保护套) fails, however, or they get stuck inside the body. A better solution would be batteries made of materials that are not toxic in the first place(从一开始、起初). Ideally, those that could safely degrade(降解、分解) inside the body.
为解决这一难题，可吞服传感器——最常见的是药丸大小的小型摄像头——通常被设计成电池不接触人体，整个装置最终随粪便排出。但有时保护外壳会失效，或者设备卡在体内。更好的方案是，从一开始就用无毒材料制造电池。最理想的情况是，这些材料能在体内安全降解。
A new study, led by Giovanni Traverso of the Massachusetts Institute of Technology and published in Nature Chemical Engineering on September 21st, demonstrates a step towards this goal: a paper-based battery whose components are safely absorbed by the body at the end of its useful life.(一项新研究向这一目标迈出了一步：由麻省理工学院的乔瓦尼·特拉韦尔索领衔、9月21日发表于《自然·化学工程》的论文展示了一种纸基电池，其组件在电池使用寿命结束后可被人体安全吸收。) The researchers reported that, in experiments with pigs, such a battery could produce a little more voltage(电压) than a standard AA cell, and enough power to run several ingestible devices for up to three days.
一项新研究向这一目标迈出了一步：由麻省理工学院的乔瓦尼·特拉韦尔索领衔、9月21日发表于《自然·化学工程》的论文展示了一种纸基电池，其组件在电池使用寿命结束后可被人体安全吸收。研究人员报告称，在猪身上进行的实验中，这种电池产生的电压略高于标准AA电池，电量足以驱动多种可吞服设备长达三天。