3D microfabrication
[2] The creation of microscopic structures is similar to conventional additive manufacturing techniques in that a computer aided design model is sliced into an appropriate number of two-dimensional layers in order to create a toolpath.
These use pulsed femtosecond lasers to deliver a precise dosage to induce absorption of energy, leading to an excited state that can result in annealing and surface structuring of a material.
These include laser chemical vapor deposition (LCVD), which use organic precursors to write patterns on a structure or bulk material.
In the end, the resist is developed in the SU-8 for about 10 to 15 minutes at the room temperature with mild agitation and then, rinsed with isopropyl alcohol.
As a result, these technology can be applied to a variety of fields like filters, mixers, jets, micro channels, light guide panels of LCD monitor and more.
Design of complicated 3D microstructure can be highly challenging task for development of novel materials for optics, biotechnology and micro/nano electronics.
Self-assembly and self-organization being the main principle of structure formation in nature attract significant interest as promising concepts for the design of intelligent materials.
Stimuli-responsive hydrogels mimic swelling/shrinking behavior of plant cells and produce macroscopic actuation in response to a small variation of environmental conditions.
Also, inhomogeneous expansion and shrinkage can result more complex behavior like bending, twisting and folding and they can happen with different magnitudes in different directions.
Utilization of these phenomena for the design of structured materials can be highly attractive because they allow simple, template-free fabrication of very complex repetitive 2D and 3D patterns.
There is an advantage of the self-folding approach, is the possibility of quick, reversible, and reproducible fabrication of 3D hollow objects with controlled chemical properties and morphology of both the exterior and the interior.
One experimental application of self-folding materials is pasta that ships flat but folds into the desired shape on contact with boiling water.
In another word, there is no method, which is cheap and large-scale production of self-folding polymer films that substantially limits their application.
To solve these issues, the future research must be focused on deeper investigation of folding to allow design of complex 3D structures using just 2D shapes.
On the other hand, searching a way, which is cheap and fast manufacturing of large quantity of self-folding films can be greatly helpful.
