Autonomous biomimetic solid dispensing using a dual-arm robotic manipulator

Abstract

Automation and robotics have the potential to transform the landscape of chemistry and materials research. However, there are still many repetitive manual processes in the laboratory that are challenging to automate. Solid dispensing is a key technique that underpins chemistry and materials science. Conventionally, a scientist weighs samples using a spatula and balance. While there are commercial implementations that automate solid dispensing, these can be costly and the methods suffer from certain limitations in terms of breadth of application, scale, and accuracy. Here, we demonstrate an automated solid dispensing system that uses a highly dexterous dual-arm robotic manipulator. The system can transfer milligram up to gram quantities of solids in a bio-mimetic fashion, mimicking the way that a scientist uses a spatula and an analytical balance. The core of this automated system is the dual-arm robot coupled with a fuzzy logic control algorithm to select the appropriate motion parameters and to manipulate spatulas of various sizes to dispense solids. Our early results suggest that this weighing method could have improved generality across a wide range of solid materials, including solids that abrade or block solid dispensing units that have moving parts. The dual-arm robot is also significantly cheaper than most commercially available solid dispensing platforms. Experiments indicate that our platform can automatically dispense solids with an accuracy as low as 2 mg, with the added functionality of resetting and dispensing again if the sample weight exceeds a predefined tolerance.