1. Department of Engineering Mechanics, Zhejiang University, Hangzhou, Zhejiang 310027, China
2. Soft Matter Research Center (SMRC), Zhejiang University, Hangzhou 310027, China
3. Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Hangzhou 310027, China
4. Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0526, USA