Research

The basis for our technology is the so-called inline holography microscopy. We shine coherent light through a transparent volume with microscopic objects like bacteria, spores, algae, microplastics, etc. in it. These objects scatter a small amount of this light. The scattered light interferes with the illumination beam, creating interference patterns that are recorded by a camera. The breakthrough technology to be further developed in this project uses recorded in-line holograms to calculate the full light field in the entire sample volume by backpropagation or numerical refocusing. This offers several advantages: 1. the ability to numerically refocus after image acquisition greatly simplifies data acquisition. 2. cells and environmental particles can be observed in their natural 3D environment. 3. it is possible to observe many more objects simultaneously than is possible with conventional microscopy, and it is possible to record a continuous flow of an analyzed fluid. Based on the data collected with this technology, Holloid aims to develop algorithms that will allow researchers and environmental analysts to simultaneously detect and quantify bacteria and microparticles using a microscope/sensor suitable for environmental monitoring, including groundwater. This will provide a new means for those responsible for water quality in the environment and, ultimately, in drinking water to gain insights with significant implications for the health of our ecosystems and people. Ultimately, the results of this project can form the basis for numerous other applications in environmental monitoring and beyond.

Biophysical properties such as mechanical and electrical properties of biological objects can serve as label-free biomarkers to reveal their physiological state and functional activities. Most conventional methods are limited by the fact that they measure an average value for the biophysical properties of an ensemble of cells. Measuring the biophysical properties of single cells is critical in biomedicine and biotechnology. For example, early-stage cancer diagnosis is only possible with single-cell analysis. In addition, the economic role of microorganisms such as yeast, bacteria and algae in food and health technology makes their individual characterization essential. The most common methods for single cell identification and characterization have not reached clinical or industrial applications due to their complex operation and very low throughput. Flow cytometry is the most common technique used in the clinical setting for cell sorting. However, it is not very specific for characterizing the biophysical properties of objects, and classical flow cytometry requires samples to be labeled, which complicates the workflow and potentially causes artifacts. The goal of this project is to develop electroacoustic spinning as a novel technique to simultaneously characterize electrical and mechanical properties of single cells with sufficient throughput, label-free, and low-cost to be industrially relevant. We will measure the electrical and mechanical properties of a large number of cells simultaneously by monitoring the rotation of the cells in an electroacoustic field between two parallel electrodes. The homogeneous electroacoustic field affects the cells equally everywhere, which allows us to evaluate the properties of many cells simultaneously.

Quantum dots (QD) are high-performance materials for optical conversion applications, such as color-generating layers in displays. The next generation of displays and other optoelectronic devices the formulation of quantum dots with high volume fraction in organic liquids, which can be printed, for example, on LEDs in LCD and micro-LED displays. Such quantum dot inks are not yet on the market and pose a particular challenge for perovskite QDs (PQDs) because they are unstable, non-uniform in size, and incompatible with organic matrices in their raw state. BrightComSol has pioneered molecular surface coatings and production methods for formulating PQDs in high viscosity polymer plastic systems with high volume fractions. We will build on this technology to develop a surface coating and synthesis method to disperse PQDs in typical ink formulations. Through a combination of resizing PQDs in the presence of such ligands and optimizing the ligands, we will realize formulations of PQDs that are colloidally stable for printing over the long term. Our new ligands and formulations will create dense shells around the small PQDs. Part of the shell will stabilize the PQD surface and crystal structure, and the other part will provide compatibility with the ink liquid. We will characterize the dispersions, from the properties of the as-synthesized PQDs to the colloidal stability to the optical properties of the ink dispersions. Our academic partners at BOKU will assist us in the selection and synthesis of novel ligands that optimize the stability of the PQDs and PQD dispersions based on their molecular architecture and physicochemical properties.