Tunable dry adhesion has a range of applications, including transfer printing, climbing robots, and gripping in automated manufacturing processes. Here, a novel concept to achieve dynamically tunable dry adhesion via modulation of the stiffness of subsurface mechanical elements is introduced and demonstrated. A composite post structure, consisting of an elastomer shell and a core with a stiffness that can be tuned via application of electrical voltage, is fabricated. In the nonactivated state, the core is stiff and the effective adhesion strength between the composite post and contact surface is high. Activation of the core via application of electrical voltage reduces the stiffness of the core, resulting in a change in the stress distribution and driving force for delamination at the interface and, thus a reduction in the effective adhesion strength. The adhesion of composite posts with a range of dimensions is characterized and activation of the core is shown to reduce the adhesion by as much as a factor of 6. The experimentally observed reduction in adhesion is primarily due to the change in stiffness of the core. However, the activation of the core also results in heating of the interface and this plays a secondary role in the adhesion change.

中文翻译：

---

通过表面刚度调制可动态调节干粘合力

可调的干附着力具有广泛的应用，包括转移印刷，爬坡机器人和自动化生产过程中的抓取。在此，介绍并演示了通过调节地下机械元件的刚度来实现动态可调的干附着力的新颖概念。制造了一种复合柱结构，该复合柱结构由弹性体壳和具有可通过施加电压来调整的刚度的芯组成。在非活化状态下，芯部是刚性的，并且复合柱和接触表面之间的有效粘合强度很高。通过施加电压激活磁芯会降低磁芯的刚度，从而导致应力分布和界面处分层的驱动力发生变化，并且 因此降低了有效粘合强度。表征了一系列尺寸范围的复合材料桩的附着力，并且显示了芯的激活将附着力降低了多达6倍。实验观察到的附着力降低主要归因于芯的刚度变化。然而，芯的活化还导致界面的加热，这在粘附力变化中起次要作用。