suo group research

Phase-transforming and switchable metamaterials

Dian Yang, Lihua Jin, Ramses V Martinez, Katia Bertoldi, George M Whitesides, Zhigang Suo

Buckling of Elastomeric Beams Enables Actuation of Soft Machines

Dian Yang, Bobak Mosadegh, Alar Ainla, Benjamin Lee, Fatemeh Khashai, Zhigang Suo, Katia Bertoldi, George M Whitesides

Silicon is a promising anode material for lithium-ion batteries due to its enormous theoretical energy density. Fracture during electrochemical cycling has limited the practical viability of silicon electrodes, but recent studies indicate that fracture can be prevented by taking advantage of lithiation-induced plasticity. In this paper, we provide experimental insight into the nature of plasticity in amorphous Li_xSi thin films. To do so, we vary the rate of lithiation of amorphous silicon thin films and simultaneously measure stresses.

Hydrogels that undergo a volume phase transition in response to an
external stimulus are of great interest because of their possible use as
actuator materials. The performance of an actuator material is normally
characterized by its force–stroke curve, but little is known about the
force–stroke behavior of hydrogels. We use the theory of the ideal
elastomeric gel to predict the force–stroke curves of a
temperature-sensitive hydrogel and introduce an experimental method for
measuring the curve. The technique is applied to PNIPAm hydrogels with
low cross-link densities. The maximum force generated by the hydrogel
increases with increasing cross-link density, while the maximum stroke