NTT Device Technology Laboratories, NTT Corporation, 3-1 Morinosato, Wakamiya, Atsugi, Kanagawa 243-0198, Japan.
ACS Appl Mater Interfaces. 2022 Oct 5;14(39):44697-44703. doi: 10.1021/acsami.2c12380. Epub 2022 Sep 12.
Ingestible electronics monitor biometric information from outside the body. Making them with harmless or digestible materials will contribute to further reducing the burden on the patient's oral intake. Here, considering that the inductive part plays an important role in communications, we demonstrate a degradable inductor fabricated with harmless substances. Such a transient component must meet conflicting requirements for both operation and disassembly. Therefore, we integrated a substrate made of gelatin, a thermally degradable material, and a precision coil pattern made of edible gold or silver leaf. However, gelatin itself lost its initial shape easily due to quick sol-gel changes in physiological conditions. Thus, we managed the gelatin's thermal responsiveness by using a tangle of gelatin/chitosan gel networks and genipin, an organic cross-linking agent, and gained insights into the criteria for developing transient devices with thermo-degradability. In addition, to compensate for the lack of water resistance and low conductivity of thin metal foils, we propose a laminated structure with oleogel (beeswax/olive oil). LCR resonance circuits, by connecting a commercial capacitor to the coil, worked wirelessly in the megahertz band and gradually degraded in a warm-water environment. The presented organic electronics will contribute to the future development of transient wireless communications for implantable and ingestible medical devices or environmental sensors with natural and harmless ingredients.
可食用电子设备可从体外监测生物特征信息。使用无害或可消化的材料制造可进一步减轻患者的口服负担。在这里，考虑到感应部分在通信中起着重要作用，我们展示了一种用无害物质制造的可降解感应器。这种瞬态元件必须满足操作和拆卸的冲突要求。因此，我们集成了由明胶（一种热降解材料）和由可食用的金或银叶制成的精密线圈图案组成的基板。然而，由于生理条件下快速的溶胶-凝胶变化，明胶本身很容易失去初始形状。因此，我们通过使用明胶/壳聚糖凝胶网络和京尼平（一种有机交联剂）的纠结来控制明胶的热响应性，并深入了解开发具有热降解性的瞬态器件的标准。此外，为了弥补薄金属箔的耐水性差和导电性低的问题，我们提出了一种具有油凝胶（蜂蜡/橄榄油）的层压结构。通过将商用电容器连接到线圈，LCR 共振电路在兆赫频段进行无线工作，并在温水环境中逐渐降解。所提出的有机电子技术将有助于未来开发具有天然无害成分的可植入和可食用医疗设备或环境传感器的瞬态无线通信。
