While some tentative first steps in AFM-IR in liquid have been made in recent years, this technique that promises nanoscale resolution chemical analysis of solid-liquid reactions and imaging of life microorganisms, is still far from routine use or wide adoption. In this work we address one of the more pressing technical issues that currently preclude wider use of liquid phase AFM-IR: the costly and unwieldy ZnSe prism sample carriers required for attenuated total reflection bottom illumination geometries. We show how they can be replaced by micro-machined Si wafers. These wafers are more flexible, chemically robust and cost effective then conventional sample carrier prisms. Through optical simulations (transfer matrix method, ray optics and finite difference time domain) we show that the micromachined wafers have similar depth of penetration as ZnSe prisms, exhibit small change in focal position during scanning and no optical hot spots or interference that might be detrimental to reproducible AFM-IR measurements. We demonstrate the use of these carriers in air and water experimentally.