Pollen is one of nature's most resilient materials and widely used as chemically stable environmental markers and in drug delivery. Recent findings show that a simple alkali treatment, similar to traditional soapmaking, can convert hard pollen grains into soft microgel particles, which exhibit stimuli-responsive changes in size and mechanical properties. Surface-based measurement approaches offer excellent potential to monitor these stimuli-responsive behaviors, however, such methods are encumbered by weakly adsorbing, free-flowing microparticles and a tendency for the microparticles to aggregate on substrates. Here, we demonstrate a facile approach to pattern soft pollen microparticles and track stimuli-responsive behaviors in situ based on a combination of chemical functionalization and scanning probe manipulation of individual microparticles. First, we prepared an amine-functionalized glass substrate that can covalently attach to carboxylic acid functional groups on the microparticle surface, tethering the particles stably. Second, we used a scanning probe cantilever to pick up and move individual microparticles to specific locations on the functionalized glass surface. Various patterns of well-separated, tethered microparticles were fabricated, including aligned arrays, hearts, and stars, and we could track the stimuli-responsive behavior of individual microparticles with in situ imaging. Taken together, this patterning concept can be broadly utilized to manipulate various classes of intelligent microparticles across fields such as diagnostics, biosensors, drug delivery, and chemo-mechanical actuators.

花粉是大自然中最有弹性的材料之一，被广泛用作化学稳定的环境标志物和药物输送。最近的发现表明，类似于传统的肥皂制造方法，简单的碱处理可以将硬花粉颗粒转化为柔软的微凝胶颗粒，从而在尺寸和机械性能方面表现出刺激响应性的变化。基于表面的测量方法为监测这些刺激响应行为提供了极好的潜力，但是，此类方法因吸附力弱，自由流动的微粒以及微粒在基材上聚集的趋势而受阻。在这里，我们演示了一种模式柔软的花粉微粒和跟踪原位刺激响应行为的简便方法。基于化学功能化和单个微粒的扫描探针操作相结合。首先，我们制备了一种胺官能化的玻璃基板，该基板可以共价连接至微粒表面的羧酸官能团，从而稳定地束缚微粒。第二，我们使用扫描探针悬臂来拾取单个微粒并将其移动到功能化玻璃表面上的特定位置。制造了各种形式的分离良好的栓系微粒，包括排列的阵列，心和星，并且我们可以通过原位追踪单个微粒的刺激响应行为成像。总而言之，这种构图概念可以广泛用于在各个领域（例如诊断，生物传感器，药物输送和化学机械致动器）操纵各种类型的智能微粒。