Many scientific instruments require a reduced pressure environment for operation. Recent developments of single chip, micro-sized instruments, such as the micro-mass spectrometer, have challenged the conventional vacuum pump's capability to generate this environment. A solution to this challenge would be a device designed to incorporate the vacuum capability within the micro-chip. This requires a change in the conventional approach from designing a modular based vacuum pump to designing a microsystem in conjunction with the vacuum capability, specifically engineered for the micro-instrument's application. The feasibility of integrating a micro-sorption pump within a micro-instrument device is demonstrated in this theoretical study. A model which relates each of the vacuum parameters, mean-free-path, pressure, volume, critical dimension and temperature, is derived for the adsorbent Spherocarb.