Self-Propelled and Electrobraking Synergetic Liquid Manipulator toward Microsampling and Bioanalysis.

Area of Science:

• Microfluidics
• Bioanalytical Chemistry
• Materials Science

Background:

• Droplet manipulation is crucial for microfluidic biochips, but current methods struggle with small sample volumes and low-temperature analysis.
• Existing techniques face challenges in capturing minute sample doses and analyzing biological samples immediately at low temperatures.

Purpose of the Study:

• To develop a self-propelled and electric stimuli synergetic droplet manipulator (SES-SDM) overcoming limitations of existing bioanalytical methods.
• To create a device capable of precise droplet capture, transport, and analysis, particularly for challenging sample types and conditions.

Main Methods:

• Femtosecond laser microfabrication and post-treatment to create the SES-SDM.
• Incorporation of bioinspired features (cactus and Nepenthes pitcher plants) including wedge structures, microbowl arrays, and silicone oil infusion.
• Utilizing ultralow voltage (4.0 V) stimuli for synergistic droplet manipulation.

Main Results:

• The SES-SDM demonstrated spontaneous and controllable droplet transport with a maximum speed of 15.7 mm/s and a long travel distance of 96.2 mm.
• The device successfully operated at -5 °C without droplet freezing, enabling accurate microdroplet capture and real-time analysis.
• Real-time diagnosis of excessive heavy metal in water was achieved through the device's self-propulsion and electro-brake capabilities.

Conclusions:

• The SES-SDM offers a robust solution for microsampling (5-20 μL) and efficient bioanalysis.
• This bioinspired manipulator provides a novel strategy for microanalysis using synergistic droplet manipulation, particularly under low-temperature conditions.
• The technology opens new avenues for developing advanced bioanalytical chips and environmental monitoring tools.