FluidFM: Combining Atomic Force Microscopy and Nanofluidics in a Universal Liquid Delivery System for Single Cell Applications and Beyond

TLDR

The fluidFM is an AFM-based system using hollow cantilevers for precise liquid dispensing and stimulation of single living cells, offering universal versatility for submicrometer experiments across biology, physics, chemistry, and materials science. The system incorporates a nanofluidic channel in the cantilever that delivers soluble molecules through a submicrometer aperture, while AFM force feedback precisely controls tip approach for localized surface modification in liquid. The fluidFM reliably distinguishes gentle cell membrane contact from perforation and enables dye delivery into individual cells and subcellular structures, demonstrating its potential to enable novel submicrometer experiments.

Abstract

We describe the fluidFM, an atomic force microscope (AFM) based on hollow cantilevers for local liquid dispensing and stimulation of single living cells under physiological conditions. A nanofluidic channel in the cantilever allows soluble molecules to be dispensed through a submicrometer aperture in the AFM tip. The sensitive AFM force feedback allows controlled approach of the tip to a sample for extremely local modification of surfaces in liquid environments. It also allows reliable discrimination between gentle contact with a cell membrane or its perforation. Using these two procedures, dyes have been introduced into individual living cells and even selected subcellular structures of these cells. The universality and versatility of the fluidFM will stimulate original experiments at the submicrometer scale not only in biology but also in physics, chemistry, and material science.