Dynamic and thermal characterization of additively manufactured pressure-fed flexures with internal fluidic channels

This paper presents the dynamic and thermal characteristics of pressure-fed flexures with the additively manufactured internal fluidic channels under various pressure and fluidic conditions. Additive manufacturing technology makes use of the mechanical design flexibility that can effectively control the material distribution in terms of stiffness and damping of the flexures. Five different fluidic channel geometries (circular, semicircular, inverse-semicircular, triangular, and inverse-triangular) with the same cross-sectional area were designed and fabricated inside of one-dimensional cantilever beams (10 × 24 × 100 mm3). Stiffness, damping ratio and natural frequency of each cantilever according to varying air pressure condition from 14.7 psi (unpressurized) to 75 psi and water-filled condition were characterized, and at the same time, dynamic behaviors of each cantilever were identified by using dynamic signal analyzer. Furthermore, the thermal behavior of the channel with respect to unpressurized air, 40 psi air, and water-flowing condition was analyzed. As a result, the internal channel geometry and filled-in media in the channel have significant influences to determine the dynamic and thermal characteristics of flexures. These results can be applied to the design of flexure mechanisms that can adaptively control or compensate for their dynamic behaviors in an easy, convenient and low-cost manner.