Skin deformation haptic devices worn on the finger pad provide realistic touch feedback during interactions with virtual objects. Two primary challenges in creating such devices are: first, making a multidegree-of-freedom device (DoF) that is small and lightweight so it does not encumber the wearer and second, providing accurate control of forces displayed to the finger pad. This work presents a 4-DoF finger pad haptic device, called Fourigami, that addresses these challenges. We address the first challenge using origami manufacturing methods and pneumatic actuation to fabricate a 25 g prototype that displays normal, shear, and twist and can be easily worn on the finger pad. We address the second challenge using a low-profile, 6-DoF, force/torque sensor to control forces displayed to the finger. Fourigami has a bandwidth ranging from 2 to 4 Hz depending on direction, and when acting on a human finger, it exerts forces ranging from$\pm$1.0 N in shear, 4.2 N in normal, and$\pm$4.2 N$\cdot$mm of twist. Finally, we demonstrate the device’s efficacy when rendering haptic feedback to a user tracking a sinusoidal trajectory and a trajectory representing interactions with a virtual object.

In response to the need for sustainable energy solutions, solar panels have gained significant traction. One way to increase the energy capture of solar systems is through solar tracking, a means of reorienting solar panels throughout the day in order to face the sun. The energy consumption increase that comes with solar tracking often far outweighs the amount of energy required to move the panel, which makes it a compelling strategy for improving solar systems. Unfortunately, while solar trackers are commonly used in large solar farms, they are rarely used on rooftops, an area where solar panels are commonly installed. This is for two primary reasons: (1) most commercially available solar trackers are too large to be installed on roofs and (2) even if traditional solar trackers were made in a more compact form-factor it would be difficult to densely lay them out on a roof without the trackers substantially shading each other. In order to address these issues, we introduce OriTrack, a small three-degree-of-freedom (3 DOF) solar tracker which reduces the area of its shadow by reducing its height as it tracks the sun. In this paper we discuss the design, manufacturing, and control of OriTrack. We then compare OriTrack to a flat reference panel, the solar energy solution commonly used on roofs today, and find that OriTrack demonstrates 23% increased energy production. This result suggests OriTrack could be used as a future solution for solar tracking on rooftops.

ReachBot is a new concept for planetary exploration, consisting of a small body and long, lightweight extending arms loaded primarily in tension. The arms are equipped with spined grippers for anchoring on rock surfaces. The design and testing of a planar prototype is presented here. Experiments with rock grasping and coordinated locomotion illustrate the advantages of low inertia passive grippers, triggered by impact and using stored mechanical energy for the internal force. Gripper design involves a trade-off among the range of possible grasp angles, maximum grasp force, required triggering force, and required reset force. The current prototype can pull with up to 8N when gripping volcanic rock, limited only by the strength of the 3D printed components. Calculations predict a maximum pull of 26N for the same spines and stronger materials.