Open microfluidic systems offer significant advantages, including the elimination of external pumps and facilitating fluid access at any point along the channel. However, their deployment in harsh environments is commonly compromised due to the delicate nature of hydrophilic chemical coatings and the vulnerability of open microchannels to clogging and contamination. Here, a bioinspired, demand-responsive mode-switchable strategy is proposed to enhance the mechanical durability of open microfluidic systems. Specifically, under harsh conditions or when long-term storage is necessary, this strategy allows the open microfluidic device to transition to a protective mode simply through releasing the strain, thereby preserving the integrity of the structure and hydrophilic coatings. The stretched open microfluidic mode enables spontaneous liquid spreading along a hydrophilic microchannel scribed by femtosecond laser. This mode-switchable strategy provides the open microfluidic device with robustness to maintain spontaneous liquid flow, even under severe testing conditions such as 2000 cycles of cotton swab rubbing, sand impact, sandpaper abrasion, tape peeling, twisting, and finger rubbing. A proof-of-concept application involving blood type analysis on this mode-switchable open microfluidic device showcases its superior mechanical durability under severe environmental conditions. The proposed strategy paves the way for the broader use of open microfluidic devices in various practical applications.

中文翻译：

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通过模式可切换策略对耐用的开放微流体通道进行飞秒激光写入


开放式微流体系统具有显著的优势，包括无需外部泵，便于在通道上的任何位置进入流体。然而，由于亲水性化学涂层的脆弱性质以及开放微通道容易受到堵塞和污染的影响，它们在恶劣环境中的部署通常会受到影响。在这里，提出了一种受生物启发的、需求响应模式可切换的策略，以提高开放式微流体系统的机械耐久性。具体来说，在恶劣条件下或需要长期储存时，这种策略允许开放式微流体装置通过释放应变来过渡到保护模式，从而保持结构和亲水涂层的完整性。拉伸的开放微流体模式使液体能够沿着飞秒激光划线的亲水微通道自发扩散。这种模式可切换策略为开放式微流体设备提供了稳健性，即使在 2000 次棉签摩擦、沙子撞击、砂纸磨损、胶带剥落、扭曲和手指摩擦等恶劣测试条件下也能保持自发液体流动。在这种模式可切换的开放式微流体设备上进行血型分析的概念验证应用展示了其在恶劣环境条件下卓越的机械耐久性。所提出的策略为开放式微流控器件在各种实际应用中的更广泛使用铺平了道路。