Four-Dimensional Printing of a Fiber-Tip Multimaterial Microcantilever as a Magnetic Field Sensor

Abstract

Metrics & MoreArticle Recommendations * sı Supporting Information ABSTRACT: "Lab on Fiber" technology integrates different micro-and nanoscale structures or materials onto optical fibers to create additional functionality. With the advanced femtosecond (Fs) laser-induced two-photon polymerization (TPP) technology, polymer microstructures printed on a fiber tip have great potential as micro-optical sensors. However, additional functionalization is usually required, which is costly and complex. Based on the advanced four-dimensional (4D) printing theory, for the first time, a successive multimaterial on-fiber TPP strategy is proposed here, and a fiber-tip polymer microcantilever-based magnetic sensor is prepared in one step. First, the cantilever and the supporting base on the fiber tip are printed by TPP, and then the magnetically responsive cube on the cantilever tip is printed with a self-made magnetic fluid photoresist. The whole process is completed in one step without additional treatment. The prepared sensor shows a minuscule size and a high magnetic sensitivity of 119 pm mT −1 in the range of 0−90 mT, suitable for weak or microspace magnetic field measurement at high spatial resolution. Especially, the proposed 4D successive on-fiber TPP strategy can be extended to other stimulus-responsive materials, providing new guidance for manufacturing various stimulus-responsive microsensors and microactuators on the fiber tip.

Ultrafast Laser 3D Nanolithography of Fiber-Integrated Silica Microdevices

“…At approximately 1383 nm, measurements revealed a free spectral range of 60 nm and a fringe visibility of about 8 dB. The observed interference pattern can be comprehended as a result of three-beam interference, originating from the fiber tip, as well as the bottom and top facets of the cantilever . When increasing the applied temperature from 24 to 900 °C, there was no change in the reflection spectra of the silica cantilever (Figure d).…”

“…The observed interference pattern can be comprehended as a result of three-beam interference, originating from the fiber tip, as well as the bottom and top facets of the cantilever. 48 When increasing the applied temperature from 24 to 900 °C, there was no change in the reflection spectra of the silica cantilever (Figure 4d). After heat treatment at 900 °C for 5 h, the dip wavelength of the spectrum also did not shift and the microcantilever maintained the intact structure, demonstrating the high-temperature stability of the fabricated functional structure.…”

Four-Dimensional Micro/Nanorobots via Laser Photochemical Synthesis towards the Molecular Scale

“…In dual/multi-layer design [ 79 , 80 ], shape-morphing happens by using different materials, forming a soft–rigid structure, where the rigid layer works as a skeleton, and the soft layer works as a muscle [ 81 ] to generate direction bending. However, according to existing analyses [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 ], the mechanical mismatch between multiple layers is a pitfall for repeated shape-morphing in actual usage.…”

“…After the introduction of versatile shape-programming strategies and the driven mechanisms of the 4DM/NRs, determining a method to predict and apply 4DM/NRs has grasped our attention [ 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 ]. To enhance the control over shape transformations while minimizing response time, researchers have been exploring nanofabrication approaches with sophisticated designs.…”

“…However, the shape-mutation-induced functional changing brings the fifth-dimensional 5D ability of optical functions into the 4DM/NRs. The 4DM/NRs possess 5D biomimetic functions of sensory function [ 109 , 110 ], chameleon-like coloration [ 111 , 112 , 113 , 114 ], dynamic optical devices [ 115 , 116 , 117 , 118 , 119 ] with variable focus, information encoding/transmission [ 120 ], wettability tailoring [ 121 ], and even electronic skin [ 122 ]. The typical 5D optical devices can be represented by color-shifted photonic crystals [ 18 ] or smart biomimetic compound eyes [ 118 ].…”