Development of Novel Platform to Predict the Mechanical Damage of a Miniature Mobile Haptic Actuator

Abstract

Impact characterization of a linear resonant actuator (LRA) is studied experimentally by a newly-developed drop tester, which can control various experimental uncertainties, such as rotational moment, air resistance, secondary impact, and so on. The feasibility of this test apparatus was verified by a comparison with a free fall test. By utilizing a high-speed camera and measuring the vibrational displacement of the spring material, the impact behavior was captured and the damping ratio of the system was defined. Based on the above processes, a finite element model was established and the experimental and analytical results were successfully correlated. Finally, the damage of the system from impact loading can be expected by the developed model and, as a result, this research can improve the impact reliability of the LRA.

2-Step Drop Impact Analysis of a Miniature Mobile Haptic Actuator Considering High Strain Rate and Damping Effects

“…The damping was modeled using a high frequency (4410 Hz), which was dominant during the energy dissipation. The damping ratio (ξ) required for the modeling was 0.02, which was based on authors’ previous measurements [7]. The constant α for the mass matrix is calculated as 1180 using Equation (3).…”

“…The moving mass, which is approximately twice that of the spring mass, is attached to the spring resulting in serious damage after the primary impact due to an internal secondary impact. Choi et al conducted a study related to the drop impact of haptic actuators [7]. They developed their finite element model using material properties, such as the microtensile strength and damping ratio, and compared the impact deformation and force using a drop test.…”

Micro/Nano Manufacturing

“…(3) Quality control of micro systems and processes. Baruffi et al [7] demonstrated the application of the replica molding technology for quality control of micro milled surfaces; Cao et al [8] investigated the effect of profile errors on the surface of micro lenses on laser beam homogenization; Choi et al [9] presented a novel testing platform to characterize and predict the mechanical damage of miniaturized haptic actuator; Gao et al [10] modeled the effect of micro manufacturing process variations on the characteristics of a micro machined doubly-clamped beam.…”

Micro/Nano Manufacturing

“…(3) Quality control of micro systems and processes. Baruffi et al [7] demonstrated the application of the replica molding technology for quality control of micro milled surfaces; Cao et al [8] investigated the effect of profile errors on the surface of micro lenses on laser beam homogenization; Choi et al [9] presented a novel testing platform to characterize and predict the mechanical damage of miniaturized haptic actuator; Gao et al [10] modeled the effect of micro manufacturing process variations on the characteristics of a micro machined doubly-clamped beam.…”