The following article is based on the Symposium X presentation given by David A. Weitz (Harvard University) on April 11, 2007, at the Materials Research Society Spring Meeting in San Francisco. The article describes how simple microfluidic devices can be used to control fluid flow and produce a variety of new materials. Based on the concepts of coaxial flow and hydrodynamically focused flow, us...

When a wetting liquid wicks into a fibrous material, it causes the material to deform. In this paper we discuss the elastocapillary effect that leads to spontaneous internal stresses in the materials. The elasto-capillary effect produced by menisci in pores can be identified through a specific stress distribution in the fibrous matrix. We show that the classical Bernoulli problem of a freely ha...

Self-bursting microcapsules, which retain their shape when suspended in water but burst quickly after the water evaporates, were proposed in a previous report. In this report, the effect of core materials on the bursting mechanism was studied. Five kinds of solvents were used as core materials, microencapsulated with polyurethane via an interfacial polymerization method. It was found that the s...

Materials with Dirac-type electronic band structure have recently drawn much interest. These materials revealed unique electrical, thermal and optical properties, which can be potentially used in future highspeed electronics. In this dissertation research, I investigate on two different classes of Dirac materials: graphene and topological insulators of the bismuth telluride (Bi2Te3) family. The...

Statistically veri®ed composite ®ngerprints and a multivariate mixing model have been employed to establish the main sources of the suspended sediment transported through the lower, non-tidal reaches of the River Ouse and one of its main tributaries, the River Wharfe, during the period 1994±1997. In the case of the suspended sediment samples collected from the River Ouse, the load-weighted mean...

The mechanical properties of materials depend strongly on crystal structure and defect configuration. Here we measure the strength of suspended single-crystal and bicrystal graphene membranes prepared by chemical vapour deposition. Membranes of interest are first characterized by transmission electron microscopy and subsequently tested using atomic force microscopy. Single-crystal membranes pre...

This paper presents the fabrication and characterization of energy harvesting thermoelectric micro generators using the commercial complementary metal oxide semiconductor (CMOS) process. The micro generator consists of 33 thermocouples in series. Thermocouple materials are p-type and n-type polysilicon since they have a large Seebeck coefficient difference. The output power of the micro generat...

Coating of dispersions or suspensions of particles in a fluid is very common in the manufacturing of functional materials. Commonly, a uniform distribution of the suspended phase is required, but, in practice, agglomerates of the suspended particles appear in the final product. It has been shown experimentally that agglomeration takes place as the dispersion flows inside the coating die, before...

Classical continuum mechanics is used extensively to predict the properties of nanoscale materials such as graphene. The bending rigidity, κ, is an important parameter that is used, for example, to predict the performance of graphene nanoelectromechanical devices and also ripple formation. Despite its importance, there is a large spread in the theoretical predictions of κ for few-layer graphene...

This article presents a novel autonomous system concept for automated construction of houses and other buildings via deposition of concrete and similar materials. The overall system consists of a novel cable-suspended mobility subsystem (a self-contained extension of the RoboCrane), a deposition nozzle subsystem, a metrology subsystem, and a material supply subsystem. This article focuses mainl...