In 2023, wearable devices will usher in new cross-border opportunities, and they will be officially included in the blood pressure measurement and hypertension diagnosis process of the 2023 "Guidelines for the Prevention and Treatment of Hypertension", and the high-precision "wrist sphygmomanometer" will immediately become an important direction for the technological development of the smart wearable industry. At present, the smart wearable devices on the market that meet international standards for blood pressure detection function mainly use micro air pumps, air bags and other structures to pressurize to achieve accurate and reliable blood pressure measurement.
Miniature piezoelectric pumps
The micro air pump is a new type of fluid pump, which uses the principle of microfluidic technology to achieve precise control of the fluid. With the rapid development of science and technology in recent years, micro pumps show high back pressure and large flow; The trend of miniaturization, low energy consumption and high-precision output. At present, the micro air pump has a variety of structural forms and driving modes, among which the micro piezoelectric pump has attracted much attention because of its simple structure and outstanding performance advantages, which can integrate the drive source part, transmission part and pump body of the traditional pump, with simple structure, small size, light weight and fast response; Application of ultrasonic technology, low noise, no electromagnetic interference, low energy consumption; The drive voltage is low, and the output small flow rate and precise air pressure can be controlled according to the applied voltage or frequency; The output torque is large, etc.
The working principle of the miniature piezoelectric pump
The miniature piezoelectric pump is composed of a piezoelectric oscillator, a pump valve and a pump body, with no motor and no rotating parts, and the piezoelectric oscillator is its power drive source, under the alternating current drive, the piezoelectric oscillator is radially shortened or elongated under the action of the electric field, and at the same time drives the elastic substrate to bend and deform, thereby changing the volume of the pump chamber. When the piezoelectric oscillator is bent forward (i.e., the piezoelectric oscillator is elongated), the volume of the pump chamber increases, the pressure in the chamber decreases, and the gas flows into the pump chamber; When the piezoelectric oscillator is bent in the opposite direction (i.e., the piezoelectric oscillator shrinks), the volume of the pump chamber decreases, the pressure in the chamber increases, and the gas is squeezed out of the pump chamber, resulting in a smooth and continuous directional flow of gas.
As a high-tech enterprise that has been deeply involved in ultrasonic technology for more than 20 years, Audiowell has rich experience in mass production of the first generation of miniature piezoelectric pumps and miniature piezoelectric fans and other related technologies. Recently, Audiwell has once again successfully overcome various technical problems and developed a new generation of miniature piezoelectric pump that integrates ultrasonic frequency band, large flow output and high pressure load.
The resonant frequency of the miniature piezoelectric pump is 245 2kHz (20 kHz), belongs to the ultrasonic frequency band, beyond the range of human hearing, the noise is as low as 40db, even if the product is worn in the middle of the night to start the intelligent detection, it will not affect the rest of others. The product is not susceptible to electromagnetic interference and has stable performance; Its piezoelectric oscillator has good toughness, good fracture resistance, strong oxidation resistance and high reliability.
There is no motor in the miniature piezoelectric pump, no rotating parts, and the structure is simple, and the air volume can be controlled only by adjusting the driving voltage or frequency, and the response is fast. If the driving voltage increases and the air pressure increases, the flow rate will be large, and vice versa. As can be seen from the following P-Q characteristic chart, the output flow rate of the product is large due to the large radial vibration of the piezoelectric oscillator, and the gas flow can still maintain positive output under a pressure load of 40 kPa.
The battery life of some brands of smart watches on the market does not meet the requirements of consumers, and the use of micro piezoelectric pumps will effectively improve the battery life of the whole machine. The miniature piezoelectric pump uses a high-performance piezoelectric oscillator as the driving source, with high electromechanical conversion rate, low product driving voltage and low power consumption of 15W, which effectively improves the battery life of the whole machine, is the best choice for smart wearable to monitor blood pressure.
The miniature piezoelectric pump is small in size (size: 21x19x3.).2mm, without air valves), light weight (weight: 3.).5G), which meets the development needs of miniaturization and lightweight technology of smart wearable devices. There is no complex structure such as traditional motors and transmission shafts inside the product, and it is not affected by friction, wear and viscous effect, with high head, no pressure and strong durability and high reliability.
After experimental testing, the miniature piezoelectric pump is connected to a 100cc container, and the time from 260mmHg to 15mmHg is reduced for 10s, and the user can quickly release the pressure restraint after using the wearable device equipped with the product to detect blood pressure, which is a better experience.
applications
Wide range of applications
Medical industry
In the medical field, miniature piezoelectric pumps can be used for the release of small amounts of sustained-release agents, including drugs such as insulin or cancer analgesia, due to their fast response and high control accuracy.
In addition, in the field of negative pressure adsorption, such as burns, medical aesthetics or obstetrics and gynecology**, miniature piezoelectric pumps can be used to manufacture thin and light electronic dressings, through its simple air volume adjustment characteristics to achieve uniform air pressure on **, extract fluid accumulation, and promote wound healing.
Consumer electronics industry
It is worth noting that in recent years, micro piezoelectric pumps also have a first-mover advantage in the field of micro heat dissipation, which can be used as a heat sink to dissipate heat for electronic devices such as chips, LEDs and PCBs of gaming and design computers.
Chemical industry
Micro piezoelectric pumps can be used in fuel cells, chip integrated cooling, microfluidic systems, microinjection systems, biochemical detection, drag reduction control and other fields.
According to the "Global Wearable Wristband Device Key Market Manufacturer Ranking in the Third Quarter of 2023" report released by Canalys, the global shipments of smart wearable wristband devices reached 51 million units in the third quarter, and the market turned from a recovery in the second quarter to a stable upward trend. Data**, the global smart wearable device market will reach about $150 billion in 2026, and the development prospects of the wearable device industry are promising. In addition, the "14th Five-Year Plan for the Development of National Aging Undertakings and Pension Service System" focuses on the research and development of wearable ambulatory ECG monitoring equipment and other physiological parameter testing equipment, and the development of portable health monitoring equipment, self-service health testing equipment and other health monitoring products. Taking advantage of the two "east winds" of market and policy, it is time for wearable device companies to "cross-border" the pension and medical industry!