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Yuhang Hu's blog

Indentation of polydimethylsiloxane submerged in organic solvents

Submitted by Yuhang Hu on

This paper uses a method based on indentation to characterize a polydimethylsiloxane (PDMS) elastomer submerged in an organic solvent (decane, heptane, pentane, or cyclohexane).  An indenter is pressed into a disk of a swollen elastomer to a fixed depth, and the force on the indenter is recorded as a function of time.  By examining how the relaxation time scales with the radius of contact, one can differentiate the poroelastic behavior from the viscoelastic behavior.  By matching the relaxation curve measured experimentally to that derived from the theory of poroelasticity, o

Using indentation to characterize the poroelasticity of gels

Submitted by Yuhang Hu on

When an indenter is pressed into a gel to a fixed depth, the solvent in the gel migrates, and the force on the indenter relaxes. Within the theory of poroelasticity, the force relaxation curves for indenters of several types are obtained in a simple form, enabling indentation to be used with ease as a method for determining the elastic constants and permeability of the gel. The method is demonstrated with a conical indenter on an alginate hydrogel.

Post-Doctoral Position in Theoretical Mechanics

Submitted by Yuhang Hu on

The University of California, Santa Barbara (UCSB), is commencing a basic research program to establish Virtual Tests for high temperature ceramic composite materials. This activity will be supported within the new National Hypersonic Science Center, Structures and Materials, which is funded by NASA and the U.S. Air Force Office of Scientific Research.The overall program involves a number of institutions, led by Teledyne Scientific Co., in Thousand Oaks, California (Drs. David Marshall and Brian Cox).

Averting cracks caused by insertion reaction in lithium-ion batteries

Submitted by Yuhang Hu on

In a lithium-ion battery, both electrodes are atomic frameworks that host mobile lithium ions. When the battery is being charged or discharged, lithium ions diffuse from one electrode to the other. Such an insertion reaction deforms the electrodes, and may cause the electrodes to crack. This paper uses fracture mechanics to determine the critical conditions to avert cracking. The method is applied to cracks induced by the mismatch between phases in crystalline particles of LiFePO4

A*STAR Investigatorship 2009: Prestigious Research Awards

Submitted by Yuhang Hu on

SERC launched the A*STAR Investigatorships in 2007.
This prestigious award for top international young research talent,
tenable at our research institutes, aims to nurture young talent and
build R&D capabilities in Singapore. This year, the award is open
for applications in the following areas:



- Cognitive Systems, including Robotics

- Metamaterials and Plasmonics

- Bioenergy and Energy Storage Technologies

- Medical Technologies for Diagnostics



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