research
Programmable 3D Self-Folding Structures with Strain Engineering
Self-assembly of three-dimensional (3D) structures, through bending, twisting, folding, and buckling, has garnered broad interest among physicists, mathematicians, chemists, and biologists. Herein strain engineering and geometric frustration as an on-demand strategy for fabricating spontaneous rolling “origami” structures with programmable multistability across multiple length scales are exploited.
Smart Laser-Writable Micropatterns with Multiscale Photo/ Moisture Reconstructible Structure
The design of a dynamic, versatile, convertible, and responsive micropatterned system is realized by a photo/moisture reconstructible multiscale film-substrate bilayer structure. Specifically, a hydrophilic polyvinyl alcohol (PVA)/laponite (LP) thin film is covalently bonded to a photothermally active polydimethylsiloxane (PDMS)/carbon black (CB) soft substrate. A laser engraver can inscribe programmable aligned micro-wrinkles by manipulating laser power and spatiotemporal control.
Dynamic thermal radiation modulators via mechanically tunable surface emissivity
Check out our paper at Materials Today: https://www.sciencedirect.com/science/article/abs/pii/S1369702120304491
Critical thresholds for mode-coupling instability in viscoelastic sliding contacts
Mode-coupling instabilities are known to trigger self-excited vibrations in sliding contacts. Here, the conditions for mode-coupling (or "flutter") instability in the contact between a spherical oscillator and a moving viscoelastic substrate are studied. The work extends the classical 2-Degrees-Of-Freedom conveyor belt model and accounts for viscoelastic dissipation in the substrate, adhesive friction at the interface and non-linear normal contact stiffness as derived from numerical simulations based on a boundary element method capable of accounting for linear viscoelastic effects.
One Ring to Bind Them...Two Rings to Rule Them
In this paper, we discuss two problems concerning scattering and localisation of flexural waves in structured elastic plates. Firstly, we compare the scattering amplitudes of waves in a thin plate, generated by a point source, due to a single mass and to a large number of smaller masses, having the same equivalent mass and located around a circle. We show that in the second case, the scattering can be reduced, in particular in the medium- and high-frequency regimes.
Global Composites Experts Webinar by Dr. Nancy Sottos
dmHUB invites you to attend the Global Composites Experts Webinar Series.
Title: Control of Reaction Fronts for Rapid Energy-Efficient Manufacturing of Multifunctional Polymers and Composites
Speaker: Dr. Nancy R. Sottos
Time: 6/3, 11AM-12PM EST.
Please go to https://www.purdue.edu/cmsc/events/2020-webinars/ to register for this webinar.
Shear fracture in bulk metallic glass composites
In situ dendrite reinforced Bulk Metallic Glass matrix composites (BMGCs) are known to overcome poor ductility and fracture response exhibited by monolithic bulk metallic glasses (BMGs). In this paper (Shear fracture in bulk metallic glass composites) recently published by our group in Acta Materialia, we report mode I and mode II fracture experiments on the above in situ BMGCs containing transforming and non-transforming dendrites.
Inversion and perversion in twist incompatible isotropic tubes
How can we induce twist in tubular structures without applying a torque?
In nature, such behavior is enabled by material anisotropy. In our new work, we show that isotropic bi-layer tubes with twist incompatible layers can twist upon inflation and extension.
Interestingly, the direction of twist can spontaneously reverse as the load increases!
Check out our new paper at EML:
https://www.sciencedirect.com/science/article/pii/S2352431621000766