Microheater-Integrated Microlens Array for Robust Rapid Fog Removal

Abstract

In extreme environments, fog formation on a microlens array (MLA) surface results in a device failure. One reliable solution for fog removal is to heat the surface using a microheater. However, due to the surface interference, the combination of these two microdevices remains elusive. In this study, we introduce lift-off and electroless plating into femtosecond laser processing to fabricate a microheater integrated MLA (μH-MLA) on the same substrate with high light transmittance, durability, and fog removal efficiency. Laser-induced micro−nano grooves enable the microheater to be tightly coupled with the MLA and have high heating performance, thus maintaining a stable performance for over 24 h during continuous operation as well as under long time ultrasonic vibration and mechanical friction. With a rapid response time (τ 0.5 ) of 17 s and a high working temperature of 188 °C, the μH-MLA removed fog that covers the entire face within 14 s. Finally, we prove the use of this fabrication method in large areas and curved surface environments. This study provides a flexible, stable, and economical method to integrate micro-optical and microelectrical devices.

EBiIn-Cu-GaIn Composite Electrodes inside Microfluidic Chips

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Wide-Size Range and High Robustness Self-Assembly Micropillars for Capturing Microspheres

“…These methods are either costly, complicated and cumbersome steps, or cannot arbitrarily design the structure size and pattern shape, resulting in low controllability and flexibility. A femtosecond laser has the advantages of high resolution, good scalability, and strong controllability, − making it one of the best choices for processing capillary force driven self-assembly microstructures. − For example, Hu et al fabricated self-assembly micropillar structures in photopolymers by femtosecond laser two-photon polymerization (TPP), with a structural height of 2–7 μm, which can capture the diameter of microspheres in 1–4.6 μm and can only capture microspheres with a diameter of less than 5 μm. Subsequently, Ni et al and Hu et al improved the efficiency of TPP technology to manufacture micropillar structures through different shaping optical fields, and its structural height was roughly 2–13 μm, the diameters of the captured microspheres were 5–10 μm, and the capture range was only slightly widened, which was still difficult to meet the requirements for the capture of larger size microspheres in practical applications.…”

Study on Deformation Behavior of Glass in High-temperature Molding for Massive Unit Microlens Arrays

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