Roadmap for Optical Tweezers 2023

Optical tweezers are tools made of light that enable contactless pushing, trapping, and manipulation of objects ranging from atoms to space light sails. Since the pioneering work by Arthur Ashkin in the 1970s, optical tweezers have evolved into sophisticated instruments and have been employed in a broad range of applications in life sciences, physics, and engineering. These include accurate force and torque measurement at the femtonewton level, microrheology of complex fluids, single micro- and nanoparticle spectroscopy, single-cell analysis, and statistical-physics experiments. This roadmap provides insights into current investigations involving optical forces and optical tweezers from their theoretical foundations to designs and setups. It also offers perspectives for applications to a wide range of research fields, from biophysics to space exploration

A microfluidic droplet system for ultra-monodisperse droplet generation:a universal approach

Abstract Despite the importance of droplet monodispersity, a universal methodology for high monodispersity droplet generation does not exist yet. We have recently demonstrated that unlike the conventional method of droplet generation, applying an identical pressure from a single source makes the microfluidic droplet system immune to the external fluctuations that originate from the imperfection of the flow source. In this work, we show that our method is universal and applicable to other common microfluidic devices and flow sources. We applied this method to flow-focusing and coflow devices that are commonly used for high-frequency microdroplet generation. In addition to the pressure pump, we used a syringe pump to show that our method is applicable to flow rate controllable systems as well. We compared the monodispersity of droplets formed by the conventional methods and the novel method explained in this work

Lab-on-a-chip platforms for disease detection and diagnosis

[No abstract available

Fabrication of nanowalled catalytically self-threaded supramolecular polyrotaxane microcapsules using droplet microfluidics

Abstract Micrometer-scale monodisperse droplets are produced to generate nanowalled supramolecular microcapsules using microfluidics for high reproducibility and high-throughput manipulation, efficient material consumption, and control over hierarchical structure, shape, and size. In this study, an optimized microfluidic droplet generation technique and a unique liquid–liquid interfacial polymerization method were applied to fabricate the monodisperse polyrotaxane–based supramolecular microcapsules in a fast and simple way. To minimize the uncertainty due to droplet volume variation, the inlet pressures were supplied from the same source while lowering the interfacial tension and the main channel hydrodynamic resistance, which are critical for high monodispersity. The target polyrotaxane network (PN) was simply formed at the interface of the water and oil phases in ultra-monodisperse microdroplets via the cucurbit[6]uril (CB6)-catalyzed azide–alkyne cycloaddition (CB6-AAC) reaction between azido- and alkyne-functionalized tetraphenylporphyrin monomers (TPP-4AZ and TPP-4AL). The thickness of the interfacially assembled PN microcapsules was 20 nm as analyzed by cross-sectional TEM and TEM-EDX techniques. The resultant water-in-oil PN microcapsules were highly monodisperse in size and able to retain target molecules. Here, rhodamine 6G (Rh6G)-loaded PN microcapsules were fabricated, and the release rate of the Rh6G cargo was investigated over time for controlled drug release applications