A Recent Development by ETU “LETI” Postgraduate Student Aims to Increase the Efficiency of a Lab-on-a-Chip

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Vladislav Lemozersky, a postgraduate student of the Department of Micro- and Nanoelectronics of ETU “LETI,” created an acoustic fluid actuator, an element that is necessary for the transport of bacteria and their clusters, cells, viruses, and other particles in the lab-on-a-chip. The development aims to improve the performance and resolution of the element and to find ways to integrate it into the lab-on-a-chip.

The lab-on-chip is one of the most anticipated gadgets in medicine. A device no larger than a mobile phone will allow analyzing samples and obtaining results much faster and without having to visit laboratories. Such systems will make the technologies for research, which is currently conducted in specialized clinical laboratories on expensive equipment, including express analysis and diagnosis of diseases, more accessible. However, when developing such devices, several problems arise with the miniaturization of fluid channels and their integration into complex multifunctional hybrid devices. The device developed by an ETU “LETI” postgraduate student helps to solve these problems.

“The device operates based on the phenomenon of surface acoustic waves that occur on the surface of a piezoelectric crystal. If a special pressure is applied to such a crystal, waves appear on its surface, which will move the particles from one module of the lab-on-chip to another,” says Vladislav.

The acoustic fluid actuator is a hybrid device: it consists of a piezoelectric and metal electrodes integrated using thick-film technology with a liquid channel system. The actuator is made on a lithium niobate substrate with flat interdigital transducers, which are two-phase electrode grids. The actuator is integrated into a microfluid system that contains channels of a certain size to match the phases of acoustic density waves in the fluid generated by the piezoelectric substrate. Modern technologies make it possible to achieve sufficient accuracy of the interdigital transducers formation, ensure the necessary accuracy of signal formation and loss reduction, and the possibility of integrating such an actuator into complex hybrid analytical systems, including disposable.

“I have been working in this direction since my bachelor’s thesis, and now I am continuing it during my postgraduate studies. I think this development is quite promising because it allows non-contact manipulation of micro- and nano-objects, i.e. it can function as acoustic tweezers, and separate particle fractions in the liquid phase, such as the erythrocytes from the blood or cells with given properties. These functions are very useful for biotechnology and will find applications in modern biomedicine including clinical analysis, organ transplantation, cellular engineering, and other applications,” says Vladislav.

At the present stage of development, acoustic fields modeling, optimization of interdigital transducers and microfluid channels topology, experimental studies of layouts in different modes, search for ways of integration into the lab-on-chip are carried out. In the future, it is planned to consider the prospects of developing autonomous separation modules for separating blood fractions on a preparative scale. Vladislav assumes that soon clinics, hospitals, and ambulance stations will receive such devices.

Researchers presented their development at the Conference of Russian Young Researchers in Electrical and Electronic Engineering IEEE (2019 ElConRus).