Laser additive manufacturing of microchannel array structure inspired by lobster eyes: Forming ability and optical focusing performance

After millions of years of evolution, nature has evolved materials and structures with excellent performance and has provided a source of inspiration for designing high-performance structures. The bionic lobster eye structure (BLES) is a typical example of imitating the good light-focusing performance of lobster eyes. Here, the BLESs with different structural parameters were designed and fabricated by laser powder bed fusion (LPBF). The experimental results demonstrated that the highest relative density of 99.98% can be obtained at a laser power of 400 W and scanning speed of 2200 mm/s, and the upper profile in each microchannel formed under this parameter was regular. All BLESs exhibited a bright central focal facula with a diffuse background on the focus plate. The light-collecting ability of LPBF-processed BLES was decreased with the increase of the upper width of microchannel (UWM), and samples with a small UWM (1.0 mm and 1.25 mm) had a good light-focusing ability. The light intensity on the analysis surface increased as the analysis surface was away from the center of BLES (optical axis), which was detrimental to the optical focusing performance. The BLES could potentially be applied to satellites to improve the efficiency of light collection of the satellite while reducing the probability of being detected.