Dip Pen Nanolithography (DPNTM) is a scanning probe technique for nanoscale lithography: A sharp tip is coated with a functional molecule (the “ink”) and then brought into contact with a surface where it deposits ink via a water meniscus. The DPN process is a direct-write pattern transfer technique with nanometer resolution and is inherently general with respect to usable inks and substrates including biomolecules such as proteins and oligonucleotides. We present functional extensions of the basic DPN process by showing actuated multi-probes as well as microfluidic ink delivery. We present the fabrication process and characterization of such active probes that use the bimorph effect to induce deflection of individual cantilevers as well as the integration of these probes. We also developed the capability to write with multiple inks on the probe array permitting the fabrication of multi-component nanodevices in one writing session. For this purpose, we fabricate passive microfluidic devices and present microfluidic behavior and ink loading performance of these components.
We report on the application as well as microfabrication process of batch-fabricated optical near-field sensors using cantilevered scanning force microscopy tips. The process includes implementation of a coaxial conductive geometry into a silicon sensor tip, along with electrical connections on the cantilever and chip body. The coaxial guide structure is used as electric lead to a sub-micron Schottky photodetector at the end of the tip, formed at the junction of the protruding silicon core and a recessed aluminum coating. The I-V curves of these sensors are consistent with numerical studies for such constricted geometries. Optical near-field data gathered by this sensor in topography-following mode is presented.