1. Haptic Ingelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart 70569, Germany
2. Schools of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
3. Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
4. Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA
5. Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
6. Zoo Atlanta, Atlanta, GA 30315, USA