Micro-Dosing of Fine Cohesive Powders Actuated by Pulse Inertia Force
AbstractMicro-dosing of fine cohesive powders is the key technology in additive manufacturing and especially in high-potency active pharmaceutical ingredients (HPAPI). However, high accuracy micro-dosing (<5 mg) of fine cohesive powder is less trivial and still remains a challenge because it is difficult to eliminate the aggregation phenomena caused by the strong interparticle cohesive forces (in small capillaries). This paper presents a novel micro-dose method of fine cohesive powders via a pulse inertia force system. A piezoelectric actuator is used to provide a high enough pulse inertia force for a tapered glass nozzle and drive powder particles in the nozzle to be discharged from the nozzle orifice with the help of particle self-gravity. The nozzles with outlet diameters in the range of 100–2000 µm were fabricated via a glass heating process. The α-lactose monohydrate powder is used as the micro-dosing powder. The influences of the tapered nozzle outlet diameter, amplitude of the applied pulse voltage, and angle of the nozzle axis on micro-dosing mass are researched. The minimum mean dose mass is 0.6 mg for a single pulse inertia force. The coefficient of variation of dose mass, which represents the micro-dosing stability, can be controlled below 5% when the dose mass is relatively small. View Full-Text
Share & Cite This Article
Wang, H.; Zhang, T.; Zhao, M.; Chen, R.; Wu, L. Micro-Dosing of Fine Cohesive Powders Actuated by Pulse Inertia Force. Micromachines 2018, 9, 73.
Wang H, Zhang T, Zhao M, Chen R, Wu L. Micro-Dosing of Fine Cohesive Powders Actuated by Pulse Inertia Force. Micromachines. 2018; 9(2):73.Chicago/Turabian Style
Wang, Hongcheng; Zhang, Ting; Zhao, Miaomiao; Chen, Rangrang; Wu, Liqun. 2018. "Micro-Dosing of Fine Cohesive Powders Actuated by Pulse Inertia Force." Micromachines 9, no. 2: 73.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.