Rigiflex, Spontaneously Wettable Polymeric Mold for Forming Reversibly Bonded Nanocapillaries

We present a novel ultraviolet (UV)-curable mold that enables the formation of reversibly bonded nanocapillaries (500−50 nm) on a gold or silicon substrate. A sheet-type (∼50 μm) polyethylene diacrylate (PEG-DA) mold was used for its rigiflex nature; it provides rigidity high enough for maintaining nanostructures (elastic modulus >70 MPa) and also flexibility good enough for intimate contact over a large area aided by weak electrostatic forces (zeta potential ≈ −113.55 mW). The electrostatic charge is generated on a rigiflex PEG-DA mold upon peeling from an original engraved silicon master by mechanical friction, thereby assisting the formation of spontaneous contact with the gold or silicon substrate.