A piezoelectric device controls droplet ejection in pharmaceutical printing through the principle of piezoelectricity. Piezoelectricity is the property of certain materials to generate an electric charge in response to mechanical stress or deformation, and conversely, to undergo mechanical deformation when subjected to an electric field. This property is utilized to precisely control the ejection of droplets in various applications, including pharmaceutical printing.
In the context of pharmaceutical printing, a piezoelectric device is often integrated into inkjet printing systems. Here's a general overview of how it works:
Piezoelectric Actuator: The core component of the piezoelectric device is a piezoelectric actuator, which is typically made of a piezoelectric material such as lead zirconate titanate (PZT). When an electric voltage is applied to the piezoelectric material, it undergoes a slight mechanical deformation, either expanding or contracting.
Ink Reservoir and Nozzle: In pharmaceutical printing, the ink or pharmaceutical solution is stored in an ink reservoir, and a tiny nozzle is used to control the ejection of droplets. The nozzle is positioned close to the printing substrate.
Ejection Process: When a droplet ejection is required, a precise and controlled electric voltage is applied to the piezoelectric actuator. This voltage causes the actuator to deform, resulting in a mechanical pressure being applied to the ink in the reservoir. This pressure forces a droplet of ink to be expelled from the nozzle.
Droplet Formation and Control: The deformation of the piezoelectric actuator is carefully controlled, allowing for the modulation of the droplet size and velocity. By varying the voltage applied to the actuator, the size of the ejected droplet can be adjusted. This level of control is crucial for ensuring accurate and consistent printing, especially in pharmaceutical applications where precise dosing is essential.
Printing Patterns: By coordinating the activation of different piezoelectric actuators in an array or by precisely controlling the timing and magnitude of the voltage pulses, intricate patterns can be printed on a substrate. In pharmaceutical applications, this enables the precise deposition of active pharmaceutical ingredients (APIs) or other materials onto substrates such as pills, tablets, or other pharmaceutical forms.
Overall, the use of piezoelectric devices in pharmaceutical printing offers high precision and control over droplet ejection, allowing for accurate and reproducible deposition of pharmaceutical substances. This technology plays a vital role in pharmaceutical research, development, and manufacturing processes where precise dosing and controlled deposition are critical factors.