No abstract

In the original publication, the section head "Methods" was incorrectly added below the title head "Development history". However, the "Methods" heading should come above the title head "3.1 Basic operations" at page number 370.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Microchannel cantilevers, one of promising physical microelectromechanical systems (MEMS) devices that have embedded microchannels, have been widely used in gravimetric sensing applications of liquids and particles introduced into the channel or dispensing/patterning applications with liquid phase materials when a dispensing nozzle is additionally configured near their free ends. Although there are numerous potential applications at elevated temperatures such as material synthesis, calorimetric measurements, and phase change mediated manipulation or control, to name a few, microchannel cantilevers are mostly used at or near room temperature mainly due to the absence of integrated active heating elements. Only for a few studies, an off-chip heater has been employed to slightly increase temperature of amicrochannel cantilever as well as its packaging/mounting structures thus both speed and range of temperature modulation were significantly limited. As an alternative, photothermal heating relying on a focused laser was recently employed but laser alignment was not user-friendly and precise quantitative heating was not straightforward due to the uncertain absorption of the incident laser. Towards various applications under fast and quantitative temperature modulation, we have developed fluidic resonators with integrated heating capability.First, we have used stainless steel tubes for proof-of-concept. By simply clamping a straight stainless steel tube on CNC-machined jigs along with piezoelectric chips, a doubly clamped tube resonator with piezoelectric actuation and detection was completed. After fabrication, basic resonant characteristics were investigated with various liquid samples at fundamental and higher flexural bending modes at room temperature. Then, the stainless-steel tube resonator under Joule heating was employed for boiling point measurements of water. The onset of the boiling inducing liquid-to-vapor transition could be detected by monitoring the resonance frequency with the aid of the phase-locked loop. After the feasibility study with the simple stainless-steel tube resonator, we have switched to microfabricated channel resonators with an integrated heater for exquisite sensitivity. Heater-integrated microchannel cantilevers with or without a dispensing nozzle were batch-fabricated via sacrificial process, ion implantation, and other typical microfabrication processes. Then, fabricated heater-integrated microchannel cantilevers were thoroughly calibrated and characterized in a variety of coupled physical domains. Upon pulsed operations, electrothermomechanical time constants extracted from the transient resonance frequency provided a new measurement modality for thermophysical properties of the fluid contained in the microchannel. When the reference solution, glycerol-water binary mixture, was pulsed heated above its boiling point, atomized droplets could be spray-ejected out of the integrated nozzle.