For different application purposes, microfluidic devices have been widely studied in recent years. As the most important parameter in microfluidic systems, pressure plays a good role in the flow pattern formation inside the channel. In general, the easiest way for pressure measurement is using gauges. However, the gauges cannot be used in microfluidic chips. In this case, the pressure of these chips can be measured with the help of a membrane and sensing channel. The technology relies on pressure-induced deformation of the elastic membrane and then the pressure can be determined from the change in capacitance at the gap caused.
For pressure sensing purposes, the novel polyimide (PI) carbon nanotube composites were fabricated by in situ polymerization using multi-wall carbon nanotubes (MWNT) as fillers. It was found that the electrical resistivity of this composite varies significantly with both the temperature and the stress in the material. In conclusion, the pressure sensor chips got great attention and have widely be used in multiple applications, such as cell culture, fluid mixing, and droplet manipulation.
Fig. 1 Microfluidic pressure sensing.1,4
Development of On-chip Micro Pressure Sensor
In the previous study, scientists have developed a novel on-chip micro pressure sensor for microfluidic pressure monitoring. The polydimethylsiloxane (PDMS) microfluidic device mainly contains a working fluid channel and a sealed detection channel beneath it. The volume of the detection channel would change with any pressure changes in the working fluid channel. In the detection channel, there is a mixture of two immiscible fluids sealed and the pressure of the working fluid can be monitored easily by measuring the interface displacement of these two fluids. Between the working channel and detection channel, the PDMS film can avoid cross-contamination between fluids. In addition, two pressure sensors can be integrated into a microchip to characterize the pressure drop in the microchannel.
Fig. 2 Schematic of microfluidic pressure sensor devices.2,4
Advantages of Pressure Sensor Chip
Relatively low cost
Simple fabrication process
Can be repeatedly used with direct current readout
Great linearity
Fast response and time stability
Creative Biolabs offers a suite of custom microfluidic chips development services to address the ever-changing research of microfluidic devices. Equipped with years of experience and advanced platforms, we can offer one-stop microfluidic solutions to meet the special needs of our clients. If you are interested in our services, please do not hesitate to contact us for more detailed information.
Published Data
The following are results highlighted in articles related to the microfluidic-based analysis in clinical diagnosis.
1. Wearable pressure sensor based on microfluidics
Fig. 3 Schematic of the microfluidic pressure sensor and the principle.3,4
A novel method has been developed to effectively bond micropatterned silicon elastomers infused with conductive fluids to polymer films, resulting in the creation of flexible microfluidic tactile or pressure sensors. The design of the microfluidic elastomer features pressure-sensitive regions and parallel arcs that connect smoothly with screen-printed electrodes. These microfluidic sensors utilize a highly conductive metallic liquid known as eutectic gallium indium (eGaIn) for optimal performance. When the pressure sensor experiences micro-deformations, fluid displacements occur, leading to variations in resistance. By mimicking a parallel circuit in the design of the microchannel, the overall resistance of the sensor is minimized, which in turn enhances its sensitivity. The resulting flexible pressure sensor demonstrates a sensitivity of 0.05 kPa-1 and is capable of effectively distinguishing mechanical loads ranging from 4 kPa to 100 kPa. Additionally, it has been engineered to withstand repeated mechanical loads without losing its structural integrity, making it a reliable option for pressure-sensing applications.
References
Islam, Doria, et al. " Piezoresistive Conductive Microfluidic Membranes for Low-Cost On-Chip Pressure and Flow Sensing." Sensors 22.4 (2022): 1489.
Jung, Yang, et al. " Highly Stable Liquid Metal-Based Pressure Sensor Integrated with a Microfluidic Channel." Sensors 15.5 (2015): 11823-11835.
Yeo, Joo Chuan, et al. "Wearable tactile sensor based on flexible microfluidics." Lab on a Chip 16.17 (2016): 3244-3250.
Distributed under Open Access license CC BY 4.0, without modification.
Q&As
Q: What types of fluids can be measured with the Pressure Sensor Chip?
A: The Pressure Sensor Chip can measure various fluids, including biological samples (such as blood and cell culture media), chemical reagents, and aqueous solutions. Its versatility makes it suitable for a wide range of applications in biomedical and chemical research.
Q: How is data from the Pressure Sensor Chip analyzed?
A: Data from the chip is collected as electrical signals, which are processed using specialized software. This software translates the signals into pressure measurements, allowing researchers to visualize and analyze pressure changes over time and make informed adjustments to their experiments.
Q: What are the advantages of using a Pressure Sensor Chip over traditional pressure measurement methods?
A: Advantages include higher sensitivity, real-time monitoring, integration with microfluidic systems, and the ability to measure small volumes of fluids. The chip’s compact design also reduces space requirements and simplifies experimental setups compared to traditional bulky pressure sensors.
Q: Can Pressure Sensor Chips be used in conjunction with other sensors?
A: Yes, Pressure Sensor Chips can be combined with other sensors, such as temperature, pH, and optical sensors, to provide comprehensive monitoring of microfluidic experiments. This multi-sensor approach allows for a more detailed analysis of the experimental conditions and outcomes.
Q: What maintenance is required for Pressure Sensor Chips?
A: Maintenance typically involves regular calibration to ensure accuracy, cleaning to prevent clogging of the microfluidic channels, and checking for any physical damage to the chip. Proper maintenance ensures the longevity and reliability of the sensors.
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Fig. 1 Microfluidic pressure sensing.1,4
Fig. 2 Schematic of microfluidic pressure sensor devices.2,4
Fig. 3 Schematic of the microfluidic pressure sensor and the principle.3,4
