Characterization of Soft Actuation Through Ultrasonic Atomization

  • Han-Joo Lee
  • Kenneth J. LohEmail author
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)


Most biological systems fully take advantage of their soft tissues by quickly reacting and interacting with the environment. This exceptional performance is possible due to flexible muscles that can bend and contract in multiple degrees-of-freedom. Since traditional robots with rigid components cannot mimic these movements, soft robotic systems fabricated from flexible elastomers are starting to receive much attention. Similarly, developing actuation techniques that can control the movement of these soft materials in multiple degrees-of-freedom is also crucial. This study proposes a new soft actuation mechanism through the use of ultrasonic atomization and small piezoelectric transducers. Unlike conventional pneumatic-based systems, this soft structure is completely untethered, which can be actuated by simply placing it above an ultrasonic transducer. First, a hollow structure was fabricated by pouring uncured elastomer into a 3D-printed mold. Second, the structure was partially filled with a small amount of liquid and placed above a piezoelectric disc. Then, exciting the transducer generated ultrasonic waves that propagated through the wall of the structure. When the amplitude of the ultrasonic wave was high enough, the liquid inside the structure was atomized and ejected small droplets inside the closed, soft chamber. These droplets rapidly evaporated and deformed the soft structure. In this work, the experimental results were compared with finite element modeling to characterize the ultrasonic-atomization-induced soft structure actuation.


Phase transformation Simulation Soft robotics Ultrasonic atomization 



This work was supported by the US National Science Foundation under grant no. CMMI-1762530. The authors acknowledge Prof. H. Alicia Kim and her research group for their collaboration. Additional support was provided by the Jacobs School of Engineering, University of California-San Diego.


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Copyright information

© The Minerals, Metals & Materials Society 2020

Authors and Affiliations

  1. 1.Materials Science and Engineering ProgramUniversity of California-San DiegoLa JollaUSA
  2. 2.Department of Structural EngineeringUniversity of California-San DiegoLa JollaUSA

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