5V flexinol air valve driver circuit using IRFZ44N FET

Hi everyone,

Using 5V Arduino Pro Mini and IRFZ44N FET, I’m trying to control a flexinol air valve http://www.robotshop.com/media/files/pdf/electrostem-2-valve.pdf in a room pressure i.e. 1-5psi.

Valve performance:
Operating voltage: MIn. 1.6V ON/ Max. 5V
Current draw: 0.8 - 2.5A
Resistance: 1.3 Ω
PDM frequency: < 5kHz
Flow rate: 3.0 ft3 / min (typical)
Response time: < 0.2 sec ON/OFF

The schematic attached here is not working and I’m not sure if the problem is caused by wrong resistor values or other issues.

Resistor value as follows:
R1 - 1KΩ
R2 - 10KΩ
R3 - 5.6Ω/5W

For the software side, i tested the FET with both digital and PWM operations.

Any suggestion will be appreciated.
s.