Volume 10, Issue 2 - Smartphone Optics & Applications

Since the development of the first light microscope over 400 years ago, the technology has continuously evolved and established itself as a powerful tool, especially in biology, diagnostics and point-of-care (PoC) applications. The miniaturization of mass-produced actuators and sensors enables the use of technically extremely complex functions in smartphones at a very low price. They can be used to implement modern microscopy methods for use in places where access to such techniques is often very limited. In this review, we show how easy it is to integrate a smartphone into the everyday microscopy-imaging routines of biology research. Such devices have also been used to identify diseases directly at the patient. Furthermore, we demonstrate how constantly increasing computing power in combination with the steadily improving imaging quality of cameras of handheld devices enables the realization of new biomedical imaging methods, which together with commercially available and 3D-printed components make current research available to a broad mass. Examples are smartphone-based super-resolution microscopy (SRM) or task-specific single-board computer-based devices, which can analyze plankton in sea water.

Magnetic levitation (MagLev) is a density-based method which uses magnets and a paramagnetic medium to suspend multiple objects simultaneously as a result of an equilibrium between gravitational, buoyancy, and magnetic forces acting on the particle. Early MagLev setups were bulky with a need for optical or fluorescence microscopes for imaging, confining portability, and accessibility. Here, we review design criteria and the most recent end-applications of portable smartphone-based and self-contained MagLev setups for density-based sorting and analysis of microparticles. Additionally, we review the most recent end applications of those setups, including disease diagnosis, cell sorting and characterization, protein detection, and point-of-care testing.

Smartphone is emerging as a portable analytical biosensing platform in many point-of-care (POC) applications such as disease diagnostics, environmental monitoring, and food toxin screening. With the recent advancement of imaging technologies on the smartphone, the manual control of acquisition settings (e.g., exposure time, frame rate, focusing distance, etc.) has already been expanded from the photo to the video capturing mode. In modern smartphone models, high frame rate (above 100 fps) can be achieved to bring in a new temporal dimension to the smartphone-supported POC tests by recording high-definition videos. This opens up a new analytical method defined as smartphone videoscopy. In this review, the recent development of smartphone videoscopy is summarized based on different POC applications. Representative examples of smartphone videoscopy systems and how these time-dependent measurements could open up new opportunities for POC diagnostics are discussed in detail. The advances demonstrated so far illustrate the promising future of smartphone videoscopy in biosensing, POC diagnostics, and time-resolved analysis in general.

The article describes the laser safety classification of a laser toy for children equipped with a laser aimer/illuminator with two radiation sources. Following the rules presented in EN 60825-1: 2014 standard, the tests and measurements of the accessible emission were carried out and the class of the laser product was determined to be 3R. It was shown that the laser toy does not comply with the requirements of the EN 62115: 2020 standard and the Public Health England Guidance. The potential hazards associated with Class 3R, indicated in the EN 60825-1: 2014 standard, are also discussed.