Automated storage and retrieval system for storing biological or chemical samples at ultra-low temperatures
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Solution Overview
Problem
Current ultra-low temperature freezer systems face inefficiencies in cooling, moisture ingress, thermal distortion issues, and premature wear due to frequent defrosting, which affects the reliability and longevity of components, especially when retrieving partial samples or dealing with sealed tubes.
Innovation Solution
An automated storage and retrieval system with a custom insulated door integrating the access module and robot drive motors, using magnetic couplings for power transmission, a dry gas curtain to reduce humidity, and a separate tube picking chamber at a subfreezing temperature to maintain sample integrity and reduce moisture ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If drive motors are mounted outside the freezer compartment, then heat generation within the ultra-low temperature storage compartment is reduced, but mechanical power transmission to internal components becomes complex and less reliable
Solution Approach 1:
The patent replaces mechanical power transmission through sealed shafts with magnetic coupling. Drive motors are mounted outside the freezer compartment, and magnetic couplings transmit rotational force through the insulated wall without physical penetration, eliminating mechanical seals and reducing moisture ingress points while maintaining temperature stability.
Solution Approach 2:
The insulated wall acts as an intermediary medium that allows magnetic field transmission while blocking thermal transfer. The magnetic coupling system uses this intermediate barrier to transmit power without compromising the thermal isolation of the ultra-low temperature storage compartment.
2Object-affected harmful factors
If the freezer compartment is sealed to prevent moisture ingress, then frost accumulation is reduced, but pressure equalization during temperature cycling becomes problematic
Solution Approach 1:
The patent extracts the pressure equalization function from the main sealed compartment by providing a separate access chamber. This allows the primary storage compartment to remain sealed for moisture prevention, while the access chamber handles pressure changes during loading and unloading operations.
Solution Approach 2:
The system is segmented into a sealed ultra-low temperature storage compartment and a separate access module. The access module can be opened for sample retrieval without compromising the seal of the main storage compartment, allowing pressure equalization without moisture ingress into the critical storage area.
3Object-generated harmful factors
If defrosting is performed by transferring all samples to another freezer, then frost is removed, but system downtime increases and sample handling complexity increases
Solution Approach 1:
The system separates the defrosting function from the main storage compartment by providing a dedicated access chamber with independent heating elements. This allows selective defrosting of the access module without affecting the ultra-low temperature storage compartment, eliminating the need to transfer samples to another freezer.
Solution Approach 2:
The access module is equipped with self-heating capability through integrated heating elements and temperature control. The system can autonomously defrost the access chamber without external intervention or sample transfer, maintaining continuous operation of the main storage compartment.
4Loss of energy
If thermal insulation is increased to reduce heat ingress, then energy efficiency improves, but system size and cost increase
Solution Approach 1:
The patent extracts non-critical functions (sample loading, unloading, and defrosting) to a separate access module with different thermal requirements. This allows the main ultra-low temperature storage compartment to have optimized thin insulation, reducing overall system size while the access module provides thermal buffer and operational flexibility.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances the efficiency of cooling, reduces the need for frequent defrosting, minimizes moisture and heat ingress, and improves the reliability of the system by maintaining sample integrity and extending component lifespan.
Implementation Method 1
Magnetic couplings provide mechanical power from robot drive motors mounted to the door outside of the ultra-low temperature compartment to robot drives inside of the ultra-low temperature compartment
Implementation Method 2
The access module is purged with a dry gas to reduce the humidity in the access module before providing access into the ultra-low temperature compartment
Implementation Method 3
The freezer body has a substantially continuous wall... The insulated freezer door is mounted to the freezer body
Data Source
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AI summary
An automated storage and retrieval system stores containers, typically- containing biological or chemical samples, at ultra-low temperatures, i.e., from about -50 -C to about -90 -C, preferably about -80 -C under normal operating conditions. Dry gas air flows are used to reduce moisture and the consequential frost within the freezer compartment. A custom insulated door is provided with an access module (22) and a tube picking compartment (30) as well as servo motors for controlling a robot (48) within the ultra-low temperature freezer compartment. The robot automatically places sample storage containers in stationary storage racks within the freezer compartment. Magnetic couplings (70, 72) are used to transmit mechanical power from outside of the freezer compartment to the robot inside of the freezer compartment. The robot has a simplified mechanical configuration. The custom door can be readily attached to standard freezer bodies.