Butterfly proboscis-inspired tight rolling tapered soft actuators

Hydrophobic-hydrophilic dichotomy of the butterfly proboscis.

Mouthparts of fluid-feeding insects have unique material properties with no human-engineered analogue: the feeding devices acquire sticky and viscous liquids while remaining clean. We discovered that the external surface of the butterfly proboscis has a sharp boundary separating a hydrophilic drinking region and a hydrophobic non-drinking region. The structural arrangement of the proboscis prov...

Tapered Rolling Bearing Thermal Studies

An apparatus to simulate the thermal behavior of a 3/4 inch bore tapered roller bearing was constructed and used to determine tapered roller bearing thermal behavior. Bearing specimens can be loaded axially and/or radially while rotating. Shaft heating is also provided and mechanical losses measured. An infrared scanner and thermocouples allow for temperature measurement. An analytical model of...

Paradox of the drinking-straw model of the butterfly proboscis.

Fluid-feeding Lepidoptera use an elongated proboscis, conventionally modeled as a drinking straw, to feed from pools and films of liquid. Using the monarch butterfly, Danaus plexippus (Linnaeus), we show that the inherent structural features of the lepidopteran proboscis contradict the basic assumptions of the drinking-straw model. By experimentally characterizing permeability and flow in the p...

Polypyrrole Soft Actuators

Geometric Gait Design for a Starfish-inspired Robot with Curvature-controlled Soft Actuators

This paper presents a geometric gait design and optimization framework for an idealized model of a planar starfish-inspired robot with curvature-controlled soft actuator arms. We describe the range of motion for each arm under the assumption of constant curvature along the length. Two modes of attachment of the ends of the arms to the ground are considered: fixed in position and orientation, an...