As a core equipment in the field of laboratory automation, the fully automatic sampling instrument revolves around precise manipulation of trace liquids and multidimensional motion control. Through the integration of non-contact piezoelectric spraying technology and precision mechanical systems, it achieves automated distribution of nano to micro upgraded droplets.

Core technical principles

Piezoelectric Jet Technology

Based on the inverse piezoelectric effect of piezoelectric ceramics, when a voltage is applied to the piezoelectric ceramic, its deformation drives the silicon wafer to bend, causing a rapid change in the volume of the cavity, thereby spraying upgrade droplets. For example, SCIENION's sciDROPNANO technology optimizes the structure of piezoelectric nozzles to control the coefficient of variation of sampling accuracy within 2%, ensuring droplet volume uniformity.

Precision Machinery Control

Using high-precision stepper motors or servo motors to drive the nozzle to move on X/Y/Z axes, the positioning accuracy can reach micrometer level. Some devices convert rotational motion into linear motion through ball screws, and combine the slide rail and crossbar structure to achieve vertical up and down movement of the needle handle. The displacement sensor provides real-time feedback on position information, forming a closed-loop control.

Intelligent software algorithm

Compensate for environmental disturbances and mechanical errors through real-time feedback and closed-loop control. For example, the STM32 based sampling instrument combined with photoelectric sensor positioning and stroke control can eliminate step loss errors of stepper motors and improve the repeatability of nano scale sampling.

Performance bottleneck analysis

Minimum sample volume limit

Under current technology, nanotip sampling relies on the collaborative optimization of piezoelectric nozzles and pumping systems. However, due to limitations in droplet surface tension and cavity design, the minimum volume is difficult to exceed the level of picotip (pL), which limits the application of ultra micro experiments.

Stability Challenge of Mechanical Systems

Under long-term operation, the stepper motor drive module is prone to generate heat, causing thermal deformation of the mechanical structure and affecting positioning accuracy. In addition, the wear problem of high-precision transmission mechanisms (such as ball screws) still needs to be solved through material optimization and lubrication technology.

Insufficient adaptability to complex samples

High viscosity or particle containing samples are prone to clogging the nozzle. Although some equipment uses hollow stainless steel tubes to penetrate the sample bottle gasket for sample suction, the stability of spot sampling for heterogeneous samples still needs to be improved.