Figure 4 Microstructure of stitching interface. SEM images of the
interfaces of two PAAm hydrogels with (A) or without (B) stitching.
Scale bar=100 µm. Sequence of fluorescent microscopic images show that
the FITC labeled CS-MA diffuses from the interface of PAAm hydrogels in
coating (C) and integrative (D) periods. Scale bar=300 µm.
3.4 Construction of 3D architectures and
microfluidic chips via layer-by-layer
adhesion
Using layer-by-layer adhesion, various architectures can be constructed
from different hydrogels. Here we provide some examples that are unable
to be fabricated by sacrificial templates. Firstly, we obtained a 3D
architecture by stitching PAAm and F127-DA hydrogel strips with CS-MA.
As shown in Figure 5A, the strips were superimposed on each other and
after stitching, the strips well bonded together, which can be pulled
without detachment (Supplementary Movie 2). Furthermore, a microfluidic
chip was assembled by three hydrogels of PAAm, F127-DA and PEG-DA,
providing an inner vascular-like channel (Figure 5B). The hydrogel chip
endured a sharp twist without cracking (Supplementary Movie 3),
indicating strong adhesion among the hydrogels.