# A Novel Piezoelectrically Driven Miniature Proportional Pneumatic Control Valve Utilizing a Microfabricated Orifice Array

Nathan P. Hagstrom, Nebiyu Fikru, Alexander M. Hargus, Thomas R. Chase

Research output: Contribution to journalArticlepeer-review

## Abstract

In this paper, we report a new valve architecture enabling the use of a piezostack actuator in miniature valves without the need for a motion amplifier. Normally, the small stroke length of the piezostack would reduce the flow capacity of the valve to a small fraction of the flow capacity of the valve orifice. The novel feature of the valve consists of replacing a single orifice with an array of micro-orifices having the same cumulative area, but each orifice having a diameter of four times the stroke length of the piezostack. The micro-orifice array enables achieving the full flow capacity of the equivalent single orifice while exploiting the low-power and high-speed capabilities of the piezostack. Using a piezostack, the open-loop linearity of proportional flow control is improved in comparison to an electromagnetically actuated valve. A prototype valve is characterized to assess the performance attributes possible with the valve architecture. The characterization of the first prototype revealed that it achieved similar flow rates to those of other miniature valves, all the while demonstrating a response time of 295 $\mu$s, and a steady-state power consumption of 41 μW.

Original language English (US) 8792954 1931-1941 11 IEEE/ASME Transactions on Mechatronics 24 5 https://doi.org/10.1109/TMECH.2019.2934405 Published - Oct 2019

### Bibliographical note

Funding Information:
Manuscript received May 19, 2018; revised February 27, 2019 and May 31, 2019; accepted July 28, 2019. Date of publication August 9, 2019; date of current version October 15, 2019. Recommended by Technical Editor K. Oldham. This work was supported in part by the National Science Foundation under Grant EEC-0540834, in part by the National Fluid Power Association Education and Technology Foundation, and in part by the National Science Foundation through the National Nano Coordinated Infrastructure Network under Award ECCS-1542202. (Corresponding author: Nathan P. Hagstrom.) The authors are with the Department of Mechanical Engineering, University of Minnesota - Twin Cities, Minneapolis, MN 55414 USA (e-mail:,hagst082@umn.edu; fikru004@umn.edu; hargu030@umn.edu; trchase@umn.edu). Digital Object Identifier 10.1109/TMECH.2019.2934405

## Keywords

• Fluid flow control
• micromachining
• piezoelectric devices
• pneumatic systems
• valves