3D‐Printed Scanning‐Probe Microscopes with Integrated Optical Actuation and Read‐Out

Abstract

realized as a sharp tip with nanometersize apex attached to a micrometer-scale cantilever. In current SPM systems, tip and cantilever are usually structured in a dedicated microfabrication process before being manually mounted and aligned to a macroscopic optomechanical system for piezoelectric actuation and optical detection of sub-nanometer movements. This concept leads to rather bulky implementations and requires laborious operation, given that the tip is a wear part that has to be regularly exchanged and re-aligned to the read-out system. In addition, tip-cantilever geo metries are currently restricted by the underlying fabrication techniques, relying on 2D lithographic patterning and subsequent anisotropic etching. These techniques usually result in pyramidal tips with rather low aspect ratios, and the dimensions of the cantilever are often subject to fabrication tolerances that lead to variations of the resonance frequency of 30% or more. [10] Moreover, current SPM systems are often limited in scanning speed, which inhibits high-throughput characterization of large sample areas. This may be overcome by arrays of SPM cantilevers for parallel scanning, [11,12] but the scalability and integration density of current SPM schemes is limited by the fact that each cantilever must still be individually addressed by a dedicated actuator and sensor element of macroscopic dimension. Chiplevel integration of individually addressable cantilevers has been Scanning-probe microscopy (SPM) is the method of choice for high-resolution imaging of surfaces in science and industry. However, SPM systems are still considered as rather complex and costly scientific instruments, realized by delicate combinations of microscopic cantilevers, nanoscopic tips, and macroscopic read-out units that require high-precision alignment prior to use. This study introduces a concept of ultra-compact SPM engines that combine cantilevers, tips, and a wide variety of actuator and read-out elements into one single monolithic structure. The devices are fabricated by multiphoton laser lithography as it is a particularly flexible and accurate additive nanofabrication technique. The resulting SPM engines are operated by optical actuation and read-out without manual alignment of individual components. The viability of the concept is demonstrated in a series of experiments that range from atomic-force microscopy engines offering atomic step height resolution, their operation in fluids, and to 3D printed scanning near-field optical microscopy. The presented approach is amenable to wafer-scale mass fabrication of SPM arrays and capable to unlock a wide range of novel applications that are inaccessible by current approaches to build SPMs.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.

Optical Fiber Integrated Functional Micro-/Nanostructure Induced by Two-Photon Polymerization

“…This hybrid photonic integration coupling induced by TPP paves the way for automated assembly of photonic multi-chip systems with unprecedented performance and versatility. For multi-fiber integrated microoptics, this group also demonstrated a highly compact scanningprobe microscopes (SPM) with integrated optical actuation and read-out (Dietrich et al, 2020), as shown in Figure 3F. The SPM engine was composed of cantilevers and probe tips, and integrates optical actuation and read-out by combining mirrors and lenses.…”

“…(E) Free-form lenses, free-form mirrors and beam expanders for the coupling between the optical fiber end face and the chip interface (Dietrich et al, 2018). (F) Scanning-probe microscope (SPM) with integrated optical actuation and read-out based on fiber array (Dietrich et al, 2020).…”

Photopolymerization Mechanisms at a Spatio-temporally Ultra-confined Light

“…Recently, it was shown that scanning-probe microscopy (SPM) engines consisted of cantilevers, tips, a wide variety of actuator and read-out elements can be produced employing MPL. It is expected, that MPL could enable a mass fabrication of SPM arrays, which is unavailable by current approaches [259]. Combining MPL with electrochemical deposition, thermal evaporation, or sputtering truly arbitrary 3D design magnetic nanostructures (magnetic nanowires, multi-segmented nanowires, nanotubes, etc.)…”

O-FIB: far-field-induced near-field breakdown for direct nanowriting in an atmospheric environment

“…Much effort has been devoted to improving the processing accuracy, and spatial resolutions as low as micrometers have been achieved in laser cutting, welding, marking, and stereolithography in an atmospheric environment [3][4][5][6] . The femtosecond laser (fs laser) is a particularly promising approach from this point of view, in addition to its three-dimensional (3D) processing capability [7][8][9][10][11][12] and broad-spectrum material usability [13][14][15][16][17][18] . Sub-diffractionlimited feature sizes at a level of tens of nanometers based on multiphoton absorption 19,20 , thresholding 21 , shrinkage 22,23 , and stimulation emission depletion effect 24,25 , have also been realized in fs-laser-induced photocuring of polymers, which unfortunately are not applicable to solid materials.…”