Department of Mechanical Engineering Texas A&M University College Station, Texas 77843, United States.
ACS Nano. 2014 Mar 25;8(3):2377-86. doi: 10.1021/nn405893t. Epub 2014 Feb 17.
Thermoelectric energy conversion is very effective in capturing low-grade waste heat to supply electricity particularly to small devices such as sensors, wireless communication units, and wearable electronics. Conventional thermoelectric materials, however, are often inadequately brittle, expensive, toxic, and heavy. We developed both p- and n-type fabric-like flexible lightweight materials by functionalizing the large surfaces and junctions in carbon nanotube (CNT) mats. The poor thermopower and only p-type characteristics of typical CNTs have been converted into both p- and n-type with high thermopower. The changes in the electronic band diagrams of the CNTs were experimentally investigated, elucidating the carrier type and relatively large thermopower values. With our optimized device design to maximally utilize temperature gradients, an electrochromic glucose sensor was successfully operated without batteries or external power supplies, demonstrating self-powering capability. While our fundamental study provides a method of tailoring electronic transport properties, our device-level integration shows the feasibility of harvesting electrical energy by attaching the device to even curved surfaces like human bodies.
热电能量转换在捕获低品位余热以向小型设备（如传感器、无线通信单元和可穿戴电子设备）供电方面非常有效。然而，传统的热电材料往往不够坚固、昂贵、有毒且笨重。我们通过对碳纳米管（CNT）垫中的大表面和结进行功能化，开发了 p 型和 n 型的纤维状柔性轻质材料。典型 CNTs 的热电功率差和仅 p 型特性已转变为具有高热电功率的 p 型和 n 型。通过实验研究了 CNTs 的能带图变化，阐明了载流子类型和较大的热电功率值。通过我们的优化器件设计，最大限度地利用温度梯度，成功地无需电池或外部电源运行电致变色葡萄糖传感器，展示了自供电能力。虽然我们的基础研究提供了一种调整电子输运特性的方法，但我们的器件级集成表明，通过将器件附着在人体等甚至弯曲的表面上，就可以实现收集电能的可行性。
