Scanning Droplet Adhesion Microscope – Towards better understanding of surface wetting

Scanning Droplet Adhesion Microscopy (SDAM) is a patented analytical technique designed for measuring wetting adhesion forces down to nanonewtons. Its unprecedented sensitivity and force range from 10 nN to 1 mN provides high versatility. With the unique ability to map submillimeter variations in surface wettability, SDAM allows visualization of wetting properties in the form of wetting maps.  

How it works

SDAM is a technology that comprises a vertically mounted force sensor with a liquid droplet probe (e.g. water) and a multi-axis sample stage for measuring normal forces. The user-friendly software enables automated surface mapping with customizable measuring parameters.

Measurement procedure for SDAM. Aalto University / Maja Vuckovac & Ville Liimatainen


  • Force resolution down to 10 nN
  • Spatial resolution down to 10 µm
  • Accurate wetting adhesion force measurements, even on extremely repellent surfaces
  • Allows detection of small but meaningful variations in wetting properties
  • Quantitative detection of pinning and depinning events on microstructures
  • Does not require line-of-sight on the liquid-surface contact – can measure curved or topographically varied surfaces
  • Suitable for measurements with a wide range of liquids
  • Visualization of wetting variations in the form of wetting maps
  • Programmable automated measurements:
  • Flexible measurement patterns – point measurements, line scanning or 2D surface mapping:


  • Macroscopically rough surfaces:
    Biological or artificial surfaces, soft surfaces in the textile industry and microfabricated patterns.
  • Microscale features:
    Investigation of the wetting properties of challenging microscopic functional features such as biochips, MEMS, chemical sensors, individual fibers, nonwovens, insect legs and eyes, human hair, and individual microstructures.
  • Local variations and surface homogeneity:
    The high lateral resolution of SDAM enables the detection of minute spatial variations in the wettability of functional surfaces, such as defects leading to failures of self-cleaning, anti-corrosion and anti-biofouling products.
  • Dynamic events:
    Early-stage surface degradation (aging, wear, etc.) detection and assessment by accurate measurement of the slightest changes in surface properties.
  • Absorbent surfaces:
    Surface liquid absorption estimation as a function of time, e.g., in pharmaceutical products, paper, and personal care products.