digital microfluidics

Digital microfluidics, also known as lab-on-a-chip technology, has numerous advantages in the field of life science research. Including its high potential in portability and significant reduction in the consumption of (rare or expensive) reagents or samples. Other significant advantages include the high-throughput capacity provided by the system and the fact that it does not require excessive power consumption due to its small size.

Digital microfluidics, also known as lab-on-a-chip technology, has numerous advantages in the field of life science research. Including its high potential in portability and significant reduction in the consumption of (rare or expensive) reagents or samples. Other significant advantages include the high-throughput capacity provided by the system and the fact that it does not require excessive power consumption due to its small size. as follows:

The advantages of digital microfluidics:

1. Reduce reagent and sample consumption

Microfluidic technology can achieve control of droplet volume in microliters or even nanoliters. This discrete droplet control method has stronger flexibility, greatly reducing reagent consumption and improving the utilization of reagents and samples.

For example, diagnostic tests only require taking 50 microliters of blood (approximately the size of a raindrop) from a patient to perform multiple tests, which is of great significance for newborns.

2. Fast diagnostic speed

It can control droplets of sub microliter size to achieve rapid reactions. These droplets are quickly operated and produce results in a fully automated system, improving the efficiency of analysis and detection.

3. Parallel execution of multiple tests

It can be automated and programmed for control. The programmable control of liquids allows for multiple analyses to be performed simultaneously on the same chip, reducing the consumption of manpower and the impact of human operation errors to a certain extent, and lowering the requirements for technical personnel.

4. Low instrument cost and small footprint

The chip design is simple, cost-effective, and has strong scalability, providing a research foundation for high-throughput analysis. Therefore, microfluidic driven testing platforms not only reduce reagent costs, but also significantly reduce chip design and manufacturing costs.

Principle and working mode:

1. Droplet generation and control:

In digital microfluidics, liquids exist in the form of tiny droplets. Each droplet is individually controlled on the electrode array, and the electrodes generate electricity (e.g. electric field or electrode voltage difference) by applying a local electric field, causing the droplet to move on the surface.

The main use is the electro wetting effect. In this effect, droplets change their contact angle on different electrodes according to changes in the electric field, thereby pushing the droplets to move in a specific direction.

2. Electro wetting effect:

When a voltage is applied to the electrode, the contact angle between the droplet and the electrode surface changes. If the electric field strength on the electrode is sufficient, the droplet will move in the direction of the electric field. By controlling different electrodes, droplets can move along a predetermined path on the entire chip surface.

3. Control operation of droplets:

Handling: By changing the voltage of the electrode array, droplets can move along a predetermined path. This movement method can achieve precise transportation of droplets.

Synthesis and Reaction: Multiple droplets can converge at specific locations for chemical reactions or other operations. For example, by applying an electric field in a specific area, droplets can synthesize or mix different reagents at specific locations.

Separation and distribution: Different droplets can be separated or distributed by adjusting the electric field. Can achieve high-throughput distribution and sample processing.

Early biochips were based on the idea of DNA microarrays, which were a glass, plastic, or silicon substrate on which DNA (probe) fragments were fixed onto the microarray. Similar to DNA microarrays, protein arrays are microarrays in which many different capture agents (commonly monoclonal antibodies) are deposited on the surface of the chip. They are used to determine the presence and/or quantity of proteins in biological samples, such as blood. The disadvantage of DNA and protein arrays is that they are neither reconfigurable nor scalable after recombinant manufacturing. Currently, digital microfluidics has been described as a means of conducting digital PCR.