Department of NanoEngineering, University of California, San Diego , La Jolla, California 92093, United States.
Department of Aerospace Engineering, San Diego State University , San Diego, California 92182-1308, United States.
ACS Sens. 2017 Dec 22;2(12):1860-1868. doi: 10.1021/acssensors.7b00729. Epub 2017 Dec 1.
Despite tremendous recent efforts, noninvasive sweat monitoring is still far from delivering its early analytical promise. Here, we describe a flexible epidermal microfluidic detection platform fabricated through hybridization of lithographic and screen-printed technologies, for efficient and fast sweat sampling and continuous, real-time electrochemical monitoring of glucose and lactate levels. This soft, skin-mounted device judiciously merges lab-on-a-chip and electrochemical detection technologies, integrated with a miniaturized flexible electronic board for real-time wireless data transmission to a mobile device. Modeling of the device design and sweat flow conditions allowed optimization of the sampling process and the microchannel layout for achieving attractive fluid dynamics and rapid filling of the detection reservoir (within 8 min from starting exercise). The wearable microdevice thus enabled efficient natural sweat pumping to the electrochemical detection chamber containing the enzyme-modified electrode transducers. The fabricated device can be easily mounted on the epidermis without hindrance to the wearer and displays resiliency against continuous mechanical deformation expected from such epidermal wear. Amperometric biosensing of lactate and glucose from the rapidly generated sweat, using the corresponding immobilized oxidase enzymes, was wirelessly monitored during cycling activity of different healthy subjects. This ability to monitor sweat glucose levels introduces new possibilities for effective diabetes management, while similar lactate monitoring paves the way for new wearable fitness applications. The new epidermal microfluidic electrochemical detection strategy represents an attractive alternative to recently reported colorimetric sweat-monitoring methods, and hence holds considerable promise for practical fitness or health monitoring applications.
尽管最近做了大量努力，但非侵入性汗液监测仍远未实现其早期分析承诺。在这里，我们描述了一种通过光刻和丝网印刷技术杂交制造的灵活表皮微流控检测平台，用于高效快速的汗液采样以及葡萄糖和乳酸水平的连续实时电化学监测。这种柔软的、贴肤的装置巧妙地融合了芯片实验室和电化学检测技术，集成了一个小型化的柔性电子电路板，用于实时无线数据传输到移动设备。对器件设计和汗液流动条件的建模允许优化采样过程和微通道布局，以实现有吸引力的流体动力学和检测储液器的快速填充（从开始运动后 8 分钟内）。因此，可穿戴微器件能够有效地将自然汗液泵送到含有酶修饰电极传感器的电化学检测室。该制造的设备可以轻松地安装在表皮上，而不会妨碍佩戴者，并且显示出对预期来自表皮佩戴的连续机械变形的弹性。使用相应的固定化氧化酶，通过快速产生的汗液进行乳酸和葡萄糖的电流生物传感，在不同健康受试者的循环活动期间进行无线监测。这种监测汗液葡萄糖水平的能力为有效管理糖尿病带来了新的可能性，而类似的乳酸监测则为新的可穿戴健身应用铺平了道路。新的表皮微流控电化学检测策略代表了对最近报道的比色汗液监测方法的有吸引力的替代方案，因此在实际健身或健康监测应用中具有很大的潜力。
