NanoScience Technology Center (NSTC), University of Central Florida, Orlando, FL, 32826, USA.
Department of Materials Science & Engineering, University of Central Florida, Orlando, FL, 32816, USA.
Sci Rep. 2019 Sep 30;9(1):14008. doi: 10.1038/s41598-019-50386-8.
We demonstrate use of makerspace techniques involving subtractive microtechnologies to fabricate micromilled microneedles (µMMNs) of stainless steel (SS) for precise delivery of agrochemicals into vascular bundles of plant tissue. Precision delivery is of immense importance for systemic pathogen control in specific areas of plant tissue. Optimization of the micromilling allows for selective removal of SS at the microscale and the microfabrication of a 5 × 5 array of µMMNs having both base width and height of 500 µm to enable precise puncture into the stem of citrus saplings. Atomic Absorption Spectroscopy reveals up to 7.5× increase in the uptake of a therapeutic cargo while Scanning Electron Microscopy reveals that specific sites of the vascular bundle; either xylem or the phloem can be uniquely targeted with customized µMMNs. Such rapid and cost-effective customization with intricate designs along with scalability is enabled by makerspace microfabrication. Additionally, a 19 × 20 array of micromilled mesoneedles has been fabricated and affixed to a paint roller as an applicator system for real-world field testing outside the laboratory. Initial results indicate reliable behavior of the applicator system and the technique can be applied to the systemic delivery of agrochemicals while conserving the loss of the agrochemical with increased application efficiency.
我们展示了使用制造空间技术（涉及减法微技术）来制造用于将农用化学品精确递送到植物组织维管束中的不锈钢（SS）微铣微针（µMMN）的方法。精确递送对于在植物组织的特定区域内进行系统性病原体控制具有重要意义。微铣削的优化允许在微尺度上选择性地去除 SS，并进行 5×5 的 µMMN 微阵列的微制造，其基底宽度和高度均为 500µm，从而能够精确刺穿柑橘树苗的茎。原子吸收光谱法显示，治疗性货物的摄取量增加了 7.5 倍，而扫描电子显微镜显示，血管束的特定部位，无论是木质部还是韧皮部，都可以用定制的 µMMN 进行独特靶向。这种通过制造空间微制造实现的快速、经济高效的定制化以及复杂设计的可扩展性。此外，还制造了一个 19×20 的微铣削中针阵列，并将其固定在油漆滚刷上作为实际田间试验的施药系统。初步结果表明施药系统可靠，该技术可用于农用化学品的系统性递送，同时提高应用效率，减少农用化学品的损失。
