标题：Continuously tuning the resonant characteristics of microcantilevers by a laser induced photothermal effect
作者：Gao, Naikun; Luo, Wenyao; Yan, Weishan; Zhang, Dongdong; Liu, Duo
作者机构：[Gao, Naikun; Luo, Wenyao; Yan, Weishan; Zhang, Dongdong; Liu, Duo] Shandong Univ, State Key Lab Crystal Mat, 27 South Shanda Rd, Jinan 250100, Shando 更多
通讯作者：Liu, D;Liu, Duo
通讯作者地址：[Liu, D]Shandong Univ, State Key Lab Crystal Mat, 27 South Shanda Rd, Jinan 250100, Shandong, Peoples R China.
来源：JOURNAL OF PHYSICS D-APPLIED PHYSICS
关键词：microcantilever; photothermal excitation; nonlinear response; vibration; frequency; detection limit
摘要：Microcantilever sensors are ultrasensitive devices with miniaturized size and fast responding capability. However, they are generally designed to operate in a very narrow frequency range, which has limited their applications. We present here an all-optical technique that enables efficient actuation and rapid tuning of the vibration behaviors of microcantilevers. In particular, the resonant frequency of a microcantilever beam can be continuously tuned remotely by a laser induced photothermal effect to cover a large range with boosted vibration amplitude, beneficial for improving the detection threshold for force and mass. The underlying principles for photothermal actuation and elastic nonlinearity are discussed in detail. A verification experiment proves its potentials in detecting acoustic waves with frequencies far from the initial resonant frequency of the microcantilever.