Lithium niobate: a novel multifunctional Lab-on-a-chip platform (LNLabChip)

• Applicant: Dr. Kore Hasse
• Subject Area: Microsystems ; Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering ; Synthesis and Properties of Functional Materials ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 579652860

This project focuses on the development of a novel multifunctional lithium niobate (LiNbO3, LN) platform for monolithic lab-on-a-chip applications. The ferroelectric crystal LN has a variety of physical properties, which enable a wide range of applications. For example, due to its piezoelectricity LN is a common medium for generating surface acoustic waves (SAW), which are used, e.g., for pumping fluids in microchannels, but also for trapping or sorting particles like cells. However, until today the fabrication of microchannels is limited to the surface of LN. Thus, microfluidic structures can not be fabricated in a monolithic way but cover pieces or additional samples containing the microchannels must be bonded onto the functional LN chip. LN is also a well-known platform for integrated photonics. Its nonlinear, electro-optic and acousto-optic properties allow to integrate many functions in a single chip, like nonlinear frequency conversion, or electro-optic modulation of light. Waveguides can be fabricated with different methods in LN and it can also be used as active gain medium for amplifiers and lasers when doped with, e.g. rare earth elements. In this way, it offers what is known as multifunctionality, which is lacking in most common lab-on-a-chip materials and finds many applications in sensing and metrology. In this project we target to combine the multifunctionality of LN with microfluidic structures, and optical elements such as waveguides. Selective etching, which was developed for LN in our preliminary research, allows for the fabrication of microchannel structures not only inside the volume of LN but also close to the surface. Thus, our main objective is, to use our novel fabrication strategy, to integrate SAW-based microfluidic pumping in microchannels fabricated by selective etching of fs laser inscribed structures in LN monolithically and combine this with optical analysis methods. Integrating microfluidic pumping in monolithic functional chips will significantly advance the research in the field of lab-on-a-chip devices, as currently microfluidic pumping is mostly limited to bulky external pumps. In our project work, we will explore active flow control using SAW-driven pumping mechanisms in near-surface microchannels, fabricated by selective etching of fs laser inscribed structures and the fabrications of optical elements like micro-lenses at waveguide-microchannel interfaces to allow for efficient optical analysis. Mixing fluids in microfluidic channels using SAWs will be investigated as well as detecting fluorescent particles suspended in liquid in microchannels optically. The main goal however is to combine both these microfluidic and optical functions on a LN chip. In this way this project work will pave the way to achieve a higher level of integration than the current state of the art for optofluidic lab-on-a-chip devices.

• DFG Programme: Research Grants