title: "Hot-wire" microfluidic flowmeter based on a microfiber coupler.
abstract: Using an optical microfiber coupler (MC), we present a microfluidic platform for strong direct or indirect light-liquid interaction by wrapping a MC around a functionalized capillary. The light propagating in the MC and the liquid flowing in the capillary can be combined and divorced smoothly, keeping a long-distance interaction without the conflict of input and output coupling. Using this approach, we experimentally demonstrate a "hot-wire" microfluidic flowmeter based on a gold-integrated helical MC device. The microfluid inside the glass channel takes away the heat, then cools the MC and shifts the resonant wavelength. Due to the long-distance interaction and high temperature sensitivity, the proposed microfluidic flowmeter shows an ultrahigh flow rate sensitivity of 2.183 nm/(μl/s) at a flow rate of 1 μl/s. The minimum detectable change of the flow rate is around 9 nl/s at 1 μl/s.
authors.forename: Shao-Cheng
authors.initials: SC
authors.lastname: Yan
authors.forename: Zeng-Yong
authors.initials: ZY
authors.lastname: Liu
authors.forename: Cheng
authors.initials: C
authors.lastname: Li
authors.forename: Shi-Jun
authors.initials: SJ
authors.lastname: Ge
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
authors.forename: Yan-Qing
authors.initials: YQ
authors.lastname: Lu