Design and Additive Manufacturing of a Continuous Servo Pneumatic Actuator.

Despite an emerging interest in soft and rigid pneumatic lightweight robots, the pneumatic rotary actuators available to date either are unsuitable for servo pneumatic applications or provide a limited angular range. This study describes the functional principle, design, and manufacturing of a servo pneumatic rotary actuator that is suitable for continuous rotary motion and positioning. It contains nine radially arranged linear bellows actuators with rollers that push forward a cam profile.

Corrigendum: Design of an Inkjet-Printed Rotary Bellows Actuator and Simulation of its Time-Dependent Deformation Behavior.

[This corrects the article DOI: 10.3389/frobt.2021.

Design of an Inkjet-Printed Rotary Bellows Actuator and Simulation of its Time-Dependent Deformation Behavior.

State-of-the-art Additive Manufacturing processes such as three-dimensional (3D) inkjet printing are capable of producing geometrically complex multi-material components with integrated elastomeric features. Researchers and engineers seeking to exploit these capabilities must handle the complex mechanical behavior of inkjet-printed elastomers and expect a lack of suitable design examples. We address these obstacles using a pneumatic actuator as an application case.

Vibrational Energy Redistribution between CH Stretching Modes in Alkyl Chain Monolayers Revealed by Time-Resolved Two-Color Pump-Probe Sum Frequency Spectroscopy.

The vibrational dynamics of the various CH stretching modes in a fatty acid Langmuir-Blodgett film was studied using a resonant narrowband infrared (IR) laser pulse for pumping and a broadband femtosecond IR visible pulse pair for detection in a sum frequency spectroscopy setup. The resulting two-dimensional spectra indicate that pumping either the antisymmetric methyl or methylene stretch results in the transfer of energy to the other modes on a time scale faster than 2 ps. This rapid process is followed by energy redistribution to other modes, presumably the bending and internal rotational modes, with a time constant of approximately 85 ps.