Research on PCB Plug Mechanism and Effective Control Method
A pressurized microchamber is an effective means of transporting liquid in lab-on-PCB devices. It works by storing pneumatic energy and releasing it through an opening in a microvalve. The microvalve is electrically activated, using a gold wire of about 25 m in diameter.
Lab-on-PCB devices are currently being developed for a wide range of biomedical applications, but they are not yet commercially available. However, research in this field is growing rapidly and there is a significant potential for obtaining marketable devices. Various flow-driving methods have been developed, including electrowetting on dielectrics, electroosmotic flow driving, and phase-change-based flow driving.
The use of external sources for moving liquids inside lab-on-PCB systems has long been used in research, but it is not a particularly practical solution for a portable system. External syringe pumps also reduce the portability of the device. However, they provide an interesting opportunity to integrate sensors and actuators in a microfluidic device.
Electroosmotic pumps are also commonly integrated on PCBs for fluid manipulation. They offer a low-cost, pulse-free continuous flow of fluid, but require narrow microchannels and external liquid reservoirs. Inappropriate activation can result in electrolysis and microchannel blocking. Moreover, copper electrodes are not ideal because they can cause fluid contamination and microchannel blocking. Further, copper electrodes require additional fabrication steps and increase cost.
Laboratory-on-PCBs (LoP) is a type of device that integrates an electronic circuit onto a PCB. This type of device is used to perform various experiments in electronic circuits. It is also used in applications that require the integration of different materials. These devices are compatible with flow-driving techniques and can also be produced by photolitographic or dry resist methods. Moreover, these devices also incorporate surface mounted electronic components that are designed to measure data. One such example is a device which integrates an embedded blue LED and an integrated temperature sensor.
Another option for moving liquids in Lab-on-PCBs is to use pressurized microchambers. The pressurized chambers can store pneumatic energy and can be released by opening a microvalve. The microvalves are activated electrically. One advantage of this type of mechanism is that it is portable and can be used multiple times. Moreover, it can withstand high pressures.
One of the main challenges of implementing microvalves into PCBs is the difficulty of integrating them into the PCB. It is also difficult to integrate actuators with moving parts into a PCB. However, researchers have developed micropumps that are PCB-based, and made use of piezoelectric actuators.
The process of using lab-on-PCBs to control liquids is highly complex and can be quite difficult. There are numerous drawbacks of this method, and the main difficulty is the complex fabrication process. Moreover, the method of assembly of LoPs also adds to the complexity of the device.