Several insect species are able to locomote across the air-water interface by leveraging surface tension to remain above the water surface. A subset of these insects, such as the stonefly and waterlily beetle, flap their wings to actively move around the two dimensional surface — a locomotion strategy referred to as interfacial flight. Here, we present an insect-scale robot, the γ-bot, inspired by these interfacial fliers. The robot is comprised of a flapping-wing vehicle that generates a thrust force parallel to the water surface, and three passive legs utilize surface tension to support the body mass and maintain contact with the air-water interface. We developed and validated a simple model to characterize the drag forces acting on the vehicle and estimate the robot’s velocity. This 112 mg robot can reach maximum velocities of 0.9 ms−1(corresponding to 15 BLs−1) and can initiate both left and right turns, demonstrating high maneuverability along the air-water interface. In addition, the robot can carry an additional 419 mg, enabling future sensing, control, and power autonomous operation.

The objective of this paper is 'open-set' speaker recognition of unseen speakers, where ideal embeddings should be able to condense information into a compact utterance-level representation that has small intra-speaker and large inter-speaker distance. A popular belief in speaker recognition is that networks trained with classification objectives outperform metric learning methods. In this paper, we present an extensive evaluation of most popular loss functions for speaker recognition on the VoxCeleb dataset. We demonstrate that the vanilla triplet loss shows competitive performance compared to classification-based losses, and those trained with our proposed metric learning objective outperform state-of-the-art methods.

The rotary electrostatic microactuators integrating optimally curved electronics are proposed to enhance the actuating force-generation capability. In most of the conventional type of electrostatic microactuators using rotary mode, the electrodes have not been rigorously evaluated in terms of optimality for the shape, but have simply been adopted in a straight shape. As a result, two neighboring electrodes should be spaced leading to a larger clearance at the outer region from the center of the rotation, hence the force generation capability is inherently limited. To overcome this limitation, the optimally curved electrode shape is introduced by tilting the electrodes in a continuous manner along with the radius. The simulation results show an enhanced capability over the conventional shape for the current application to a hard disk drive. Microactuators were fabricated with the aspect ratio of 4:45 by using the inductively coupled plasma reactive ion etching. Experiments results obtained indicate the increased capability of the proposed type.