Finite element study on tungsten based nano-sensor for single cell intracellular temperature measurement

Single cell analysis has become an important field of research in which cells properties are studied for an improved understanding of cellular processes. Cell´s intracellular temperature has proven to be a vital element of most cellular activates, chemical reactions, cell survival and how cells react towards external stimuli. However, the current available methods do not have the required qualifications to be able to measure the temperature accurately at a micro scale level. Recently, many attempts by researchers from different fields have been done to develop sensors that have high accuracy and do not cause any damages to the cells. Here a nano-needle microfluidic system for single cell temperature measurement is proposed. The sensor design, electro-thermal and mechanical characterization are analyzed using a finite element approach in which tungsten is used as the sensing material. A rectangular shaped sensor with a gap of 10.8 μm shows to give the same current density distribution within the sensor, at 90μm cross sectional area shows to cause minimum damage to the cell. Furthermore, the current shows to have a positive temperature coefficient of resistance TCR with an increase in the temperature and the sensor reaches an equilibrium temperature in 100ns. The needle shows to be able to resist ramp force applied on it up to 22.5μm then undergoes failure.