Issue: May 2015

Millimeter-Scale Robotic Mechanisms Using Carbon Nanotube Composite Structures
May 2015

Smaller tools for robotic surgery will lead to reduced scarring and recovery times after surgery. However, the small-sized parts required for those tools are difficult to fabricate using conventional processes. In this paper, we demonstrate the fabrication of two potential tools for robotic surgery using a layered manufacturing process based on photolithography of carbon nanotube composite materials. Both tools fit into a cylinder with a 3 mm diameter, and both contain features with size on the order of 10 micrometers.

Fabrication of Composite and Sheet Metal Laminated Bistable Jumping Mechanism
May 2015

At a layer-based manufacturing method using composite microstructures, fabrication method for embedding an elastic component at an angled position is developed. Sheet metal is used as an elastic component, which is stamped after the layering and curing process, thereby changing the neutral position of the spring. By using this fabrication method, a small-scale bi-stable jumping mechanism is fabricated and can jump to a height 175mm with an initial takeoff velocity of 1.93m/s.

Integrated Manufacture of Exoskeletons and Sensing Structures for Folded Millirobots
May 2015

Our prior work has shown that the Smart Composite Microstructures (SCM) process can be applied to produce folded millirobots that do not compromise on performance. The next frontier of this research is to bring these robots outside, into unknown and hazardous environments where needs for protection and sensing will be determined by task. To make this translation we present rapid, and low-cost manufacturing methods for more robust SCM structures, protective exoskeletons that aid locomotion, anisotropic claws that double traction, integrated tactile sensing arrays, and print-in-place strain gauges. These new structures protect SCM millirobots and add to their capabilities in ways that broaden their applicability to real-world situations.

Helical Kirigami-Enabled Centimeter-Scale Worm Robot With Shape-Memory-Alloy Linear Actuators
May 2015

This work is to introduce the shape-memory-alloy (SMA) as an actuator to an origami parallel mechanism as a section of a novel worm robot. The work presents the design and manufacture of this active origami mechanism and the integrated SMA linear actuators for the worm robot. The use of SMA coil spring actuators provides a novel actuation method using linear actuators for parallel structures composed of only revolute joints, leading to actuation transference between rotary input and linear input. The presented principle of folding a flat sheet to a 3D structure is a step change approach to design and manufacture of fully-integrated robotic mechanisms.

Folding Angle Regulation by Curved Crease Design for Self-Assembling Origami Propellers
May 2015

This paper presents a self-folding origami method for automated manufacturing of three dimensional curved structures. We first investigated how the curvature design of a crease on a sheet influences the folding angle, and further exploited this feature to regulate the self-folded designs. A mathematical model for estimating the folding angle and its experimental validation are shown. We demonstrated the method by self-folding a propeller structure, which can be levitated underwater with an external magnetic field application.

Shape Deposition Manufacturing of a Soft, Atraumatic, and Deployable Surgical Grasper
May 2015

Using integrated manufacturing processes with soft constituent materials, a new paradigm of soft, smart surgical devices can be realized to drastically reduce complication risks and enable safer procedures. We have designed, prototyped, and tested a ‘soft’, atraumatic, deployable surgical grasper that can be used during robolaparoscopic surgery to provide a safe, compliant intermediary between delicate organs and the sharp, rigid robotic forceps that are used to grasp and manipulate these organs on an ad-hoc basis. Multi-jointed, conformable fingers with embedded pressure sensors can conform to complicated geometry, thereby distributing forces and providing an inherently safe means of manipulating and retracting anatomy.