Scholarlink

<p>Autonomous droplet oscillations are intriguing and provide a strong inspiration for the development of active soft matter. However, they are often limited by their reliance on external gradients and slow transport. Here, we demonstrate a propulsion mechanism driven by confined interfacial reactions: the hydrogen microbubble elevator. We show that hydrogen evolution within a liquid organic hydrogen carrier (LOHC) droplet and the resulting bubble pinch off modulate the droplet’s effective density, inducing periodic rising and sinking cycles in a stratified fluid. These droplets reach peak velocities of up to 25 mm/s over 2.5 cm trajectories - three orders of magnitude faster than typical Marangoni-driven bouncing - and sustain robust oscillatory motion for up to 25 minutes. The oscillation period and amplitude are programmable through the reaction kinetics, with motion persisting until the bubble-to-droplet size ratio exceeds a critical threshold. With a force balance model, we can quantitatively explain the experimental results and the interplay between gas evolution rates and hydrodynamic forces.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Microbubble elevator induced buoyancy oscillations of reacting droplets

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月11日

查看全文
  • Fattahi Kobra,
  • Boubakar Sanogo,
  • Qiuyun Lu,
  • Yuqi Li,
  • Ben Bin Xu,
  • Detlef Lohse,
  • Daosheng Deng,
  • Xuehua Zhang

摘要

Autonomous droplet oscillations are intriguing and provide a strong inspiration for the development of active soft matter. However, they are often limited by their reliance on external gradients and slow transport. Here, we demonstrate a propulsion mechanism driven by confined interfacial reactions: the hydrogen microbubble elevator. We show that hydrogen evolution within a liquid organic hydrogen carrier (LOHC) droplet and the resulting bubble pinch off modulate the droplet’s effective density, inducing periodic rising and sinking cycles in a stratified fluid. These droplets reach peak velocities of up to 25 mm/s over 2.5 cm trajectories - three orders of magnitude faster than typical Marangoni-driven bouncing - and sustain robust oscillatory motion for up to 25 minutes. The oscillation period and amplitude are programmable through the reaction kinetics, with motion persisting until the bubble-to-droplet size ratio exceeds a critical threshold. With a force balance model, we can quantitatively explain the experimental results and the interplay between gas evolution rates and hydrodynamic forces.