Herein, we report the first hybrid open-cell foam with
revisable
actuation. Open-cell foams with revisable actuation are favoable for
many applications. However, it is challenging to fabricate such open-cell
foams with very low density. This study presents a novel concept of
creating hybrid two-way (2W) shape memory open-cell foams using two-way
shape-memory-polymer-based syntactic foams as the matrix. Previously,
a syntactic foam prepared by incorporating hollow glass microbubbles
in the cross-linked semicrystalline cis-poly(1,4-butadiene)
(cPBD) was proved to have enhanced strength and specific energy output
compared to the neat cPBD. Here, the same syntactic foam was used
as the matrix, and the open-cell structure was produced by the salt-leaching
method. The hybrid foam exhibits very attractive properties, including
reversible actuation strain up to 50%, density as low as 0.07 g/cm3, energy output up to 0.23 J/g, tensile strength up to 0.84
MPa, elongation at break as high as 339%, high thermal stability with
peak decomposition temperature at 450 °C, and Joule heating and
strain sensing capabilities. The tensile strength and stiffness are
shown to follow the well-known Gibson–Ashby model for porous
materials. Combining the open-cell structure with the reversible actuation
and other functionalities enables numerous potential applications
for the prepared hybrid foam, including adjustable filters, insulators,
sealers, and smart scaffolds.