Non-invasive measurement of wall shear stress in microfluidic chip for osteoblast cell culture using improved depth estimation of defocus particle tracking method.

The development of a non-invasive method for measuring the internal fluid behavior and dynamics of microchannels in microfluidics poses critical challenges to biological research, such as understanding the impact of wall shear stress (WSS) in the growth of a bone-forming osteoblast. This study used the General Defocus Particle Tracking (GDPT) technique to develop a non-invasive method for quantifying the fluid velocity profile and calculated the WSS within a microfluidic chip. The GDPT estimates particle motion in a three-dimensional space by analyzing two-dimensional images and video captured using a single camera.

Rolling circle amplification and graphene-based sensor-on-a-chip for sensitive detection of serum circulating miRNAs.

In this study, we developed a simple multiplex miRNA detection platform based on rolling circle amplification and the fluorescence quenching property of reduced graphene oxide. The detection platform could be applied on a microfluidics chip with a mobile system controller to eliminate contamination and to facilitate potential use in remote areas. As a proof of concept, two fluorescence-labeled ssDNA tags were used for detection of miR-29a and miR-144*, two miRNAs that are highly expressed in the blood circulation of some patients with cancer or tuberculosis.

Piezoelectric-Induced Triboelectric Hybrid Nanogenerators Based on the ZnO Nanowire Layer Decorated on the Au/polydimethylsiloxane-Al Structure for Enhanced Triboelectric Performance.

Here, we demonstrate a novel device structure design to enhance the electrical conversion output of a triboelectric device through the piezoelectric effect called as the piezo-induced triboelectric (PIT) device. By utilizing the piezopotential of ZnO nanowires embedded into the polydimethylsiloxane (PDMS) layer attached on the top electrode of the conventional triboelectric device (Au/PDMS-Al), the PIT device exhibits an output power density of 50 μW/cm, which is larger than that of the conventional triboelectric device by up to 100 folds under the external applied force of 8.5 N.