Using a 3D printer and detailed computer simulations, researchers from the Massachusetts Institute of Technology produced soft material with controllable surface textures that can be varied by squeezing. By creating smooth, ridged, or custom-patterned surfaces at will, the technique will allow users to design the highly complex microfluidic channels needed in chemical or biological detectors.
The material is composed of two polymers with different degrees of stiffness. When squeezed, the material’s surface changes from smooth to a pattern determined by the spacing and shapes of the implanted harder particles; when released, it reverts back to the original form.
The system produced simple, repetitive patterns of bumps or creases, which could also be useful for changing the aerodynamic resistance of an object, or its reflectivity.
While the research used physical pressure to control texture, the same design principles could be used to modify materials using other stimuli, such as through application of an electric charge, or by changing temperature or humidity.