Acoustic microbubbles (MBs) are an important class of biomaterials that play an increasingly prominent role in advanced applications such as contrast and super-resolution imaging, sonoporation, drug delivery, microrobotics, and biosensors. The ability to control and regulate acoustic cavitation of MBs by ultrasound (US) pulses is fundamental to achieve these applications. However, most MBs are coated with a soft shell that may undergo alteration (e.g., rupture or dissolution) under insonification and result in unintended acoustic responses. This work introduces a system of stable polymeric caged MBs in which the gas core is encapsulated within a rigid but nanoporous shell, so that their acoustic response is regulated by both shell compressibility and metastructure (i.e., porosity), thus permitting high control over their cavitation behaviors via pulse manipulation. These caged MBs are fabricated via a method of interfacial nanoprecipitation. Fabrication parameters can be varied to manipulate shell elasticity and porosity and subsequently control a wide range of acoustic properties such as tuning resonance frequency, controlling modes of nonlinear cavitation. Furthermore, the cavitation of caged MBs can be manipulated to develop tunable acoustic pressure sensors. These caged MBs offer insight of the acoustic–material relationship to design acoustic biomaterials for US-guided diagnostic and therapeutic technologies.

中文翻译：

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用于控制声空化和压力传感的工程笼式微泡

声学微泡 (MB) 是一类重要的生物材料，在对比度和超分辨率成像、声穿孔、药物输送、微型机器人和生物传感器等先进应用中发挥着越来越突出的作用。通过超声 (US) 脉冲控制和调节 MB 声空化的能力是实现这些应用的基础。然而，大多数 MB 都涂有软壳，在声波作用下可能会发生变化（例如，破裂或溶解）并导致意外的声学响应。这项工作引入了一种稳定的聚合物笼状 MB 系统，其中气核被封装在刚性但纳米多孔的壳内，因此它们的声学响应受壳可压缩性和超结构（即孔隙率）的调节，从而允许通过脉冲操纵对其空化行为进行高度控制。这些笼状 MB 是通过界面纳米沉淀的方法制造的。可以改变制造参数以操纵壳弹性和孔隙率，并随后控制广泛的声学特性，例如调谐共振频率、控制非线性空化模式。此外，可以操纵笼式 MB 的空化来开发可调声压传感器。这些笼状 MB 提供了对声学材料关系的洞察，以设计用于美国引导的诊断和治疗技术的声学生物材料。可以改变制造参数以操纵壳弹性和孔隙率，并随后控制广泛的声学特性，例如调谐共振频率、控制非线性空化模式。此外，可以操纵笼式 MB 的空化来开发可调声压传感器。这些笼状 MB 提供了对声学材料关系的洞察，以设计用于美国引导的诊断和治疗技术的声学生物材料。可以改变制造参数以操纵壳弹性和孔隙率，并随后控制广泛的声学特性，例如调谐共振频率、控制非线性空化模式。此外，可以操纵笼式 MB 的空化来开发可调声压传感器。这些笼状 MB 提供了对声学材料关系的洞察，以设计用于美国引导的诊断和治疗技术的声学生物材料。