Surfaces with tunable adhesion based on composite structures and methods of making the same
View Patent ↗A structured composite surface includes a backing layer and a plurality of composite posts in contact with the backing layer, each composite post having a core made of a first material and an outer shell made of a second material, the outer shell is in contact with and surrounding the core, the core has a Young's modulus of at least 50 times greater than the outer shell. A method of transfer printing includes pressing a stamp including at least one composite post to a substrate, the at least one composite post having a core made of a first material and an outer shell made of a second material, the outer shell is in contact with and surrounding the core, the core has a Young's modulus at least 50 times greater than the outer shell, and retracting the stamp from the substrate by applying a shear load to the stamp.
1. A composite post adhesion structure, comprising:
a post and a backing,
the post defining a distal end and a proximal end,
the distal end of the post being attached to the backing,
the post including
(i) core comprised of a first material and
(ii) an outer shell comprised of a second material, the outer shell in contact with and surrounding the core, the core having a Young's modulus at least 50 times greater than the outer shell,
the post having a radius, r, and the post defining a longitudinal axis,
the outer shell extending along the longitudinal axis beyond the proximal end of the core by a distance, t, and t/r being less than about 0.45.
2. The composite post of claim 1 , wherein the core comprises a bottom surface having a geometry selected from the group consisting of flat, curved, and angular.
3. The composite post of claim 1 , wherein the core comprises a core axial centerline and the outer shell comprises an outer shell axial centerline, and wherein the core axial centerline and the outer shell axial centerline are superimposed.
4. A composite post comprising:
a core comprised of a first material; and
an outer shell comprised of a second material,
the outer shell in contact with and surrounding the core,
the core having a Young's modulus at least 50 times greater than the outer shell,
wherein the core comprises a core axial centerline and the outer shell comprises an outer shell axial centerline, and
wherein the core axial centerline and the outer shell axial centerline are shifted from each other.