Van Hileghem Lorenz, Kushwaha Shashwat, Piovesan Agnese, Verboven Pieter, Nicolaï Bart, Reynaerts Dominiek, Dal Dosso Francesco, Lammertyn Jeroen
Biosensors Group, Department of Biosystems, KU Leuven, Willem de Croylaan 42, 3001 Leuven, Belgium.
Institute of Micro- and Nanoscale Integration, KU Leuven, 3001 Leuven, Belgium.
Micromachines (Basel). 2023 Mar 7;14(3):615. doi: 10.3390/mi14030615.
Microneedles are gaining a lot of attention in the context of sampling cutaneous biofluids such as capillary blood. Their minimal invasiveness and user-friendliness make them a prominent substitute for venous puncture or finger-pricking. Although the latter is suitable for self-sampling, the impracticality of manual handling and the difficulty of obtaining enough qualitative sample is driving the search for better solutions. In this context, hollow microneedle arrays (HMNAs) are particularly interesting for completely integrating sample-to-answer solutions as they create a duct between the skin and the sampling device. However, the fabrication of sharp-tipped HMNAs with a high aspect ratio (AR) is challenging, especially since a length of ≥1500 μm is desired to reach the blood capillaries. In this paper, we first described a novel two-step fabrication protocol for HMNAs in stainless steel by percussion laser drilling and subsequent micro-milling. The HMNAs were then integrated into a self-powered microfluidic sampling patch, containing a capillary pump which was optimized to generate negative pressure differences up to 40.9 ± 1.8 kPa. The sampling patch was validated in vitro, showing the feasibility of sampling 40 μL of liquid. It is anticipated that our proof-of-concept is a starting point for more sophisticated all-in-one biofluid sampling and point-of-care testing systems.
在采集诸如毛细血管血等皮肤生物流体样本的背景下，微针正受到广泛关注。其微创性和用户友好性使其成为静脉穿刺或手指采血的显著替代品。尽管后者适用于自我采样，但手动操作的不实用性以及获取足够质量样本的困难促使人们寻求更好的解决方案。在这种情况下，中空微针阵列（HMNA）对于完全集成样本到答案的解决方案特别有吸引力，因为它们在皮肤和采样装置之间创建了一个通道。然而，制造具有高纵横比（AR）的尖锐尖端HMNA具有挑战性，特别是因为需要≥1500μm的长度才能到达毛细血管。在本文中，我们首先描述了一种通过冲击激光钻孔和随后的微铣削在不锈钢中制造HMNA的新颖两步制造方案。然后将HMNA集成到一个自供电的微流体采样贴片中，该贴片包含一个经过优化以产生高达40.9±1.8 kPa负压差的毛细管泵。该采样贴片在体外得到验证，显示了采集40μL液体的可行性。预计我们的概念验证是更复杂的一体化生物流体采样和即时检测系统的起点。
