Attension Theta Flow

The Attension Theta Flow is a premium contact angle meter for demanding surface studies with a high level of automation & accuracy for user-independent results.

Attension Theta Flow

The Attension Theta Flow is a premium contact angle meter for demanding surface studies with a high level of automation & accuracy for user-independent results.

Manufacturer Attension
Product Series Theta Optical Tensiometer
Measurement principle Optical Tensiometry
Application Surface Tension - Contact Angle
Sample type Chemicals, pharmaceuticals, electronics, foods, energy, paper and packaging
MeasurementsStatic/ dynamic contact angle, surface/ interfacial tension, surface free energy, 3D surface roughness, interfacial rheology

Product Overview

The Attension Theta Flow is a premium contact angle meter suitable for demanding surface research with a high level of automation. The method of analysis is to capture images of the liquid sample drop as forms at the end of a syringe. The drop changes shape with time and the sequence of images is analysed to determine contact angle and surface tension. Measurements are made in air or on a surface. In air, the drop is formed at the end of a precision syringe and a camera captures its images. When a drop of sample is placed on a solid surface it spreads and forms a profile that depends on the solid’s surface free energy. The camera captures the image of the drop profile and a fitting method is used to determine contact angle and surface tension. Optical tensiometry measurements are used to determine properties such as wettability, adhesion, adsorption, cleanliness, heterogeneity, spreading, printability, emulsion and foam stability.

The Theta Flow brings a higher level of automation to simplify measurements and increase accuracy. Each step is automated, from droplet creation to placement on the sample and movement of the sample stage. This enables the fully automated measurement of key parameters like contact angle, surface free energy (SFE), surface tension, and interfacial tension.

The touch display on the Theta Flow improves the user experience by simplifying the measurement setup which is completed within seconds, from filling the liquids to changing samples. The 5MP camera combined with Autofocus and DropletPlus technology provides superior image quality to ensure highly accurate results. DropletPlus increases the contrast and the sharpness of the baseline to maximise visibility and therefore assists the automatic baseline and drop shape analysis. Integrated temperature and relative humidity sensors keep track of the surrounding environment for good traceability.  The OneAttension software provides comprehensive analysis of drop shapes. It uses the Young-Laplace equation as a reference method and can fit the entire drop profile. The user interface enables live analysis and includes a database of liquid properties.

Measurements include,

  • Static contact angle: Sessile drop, captive bubble and meniscus methods
  • Dynamic contact angle: Dynamic contact angle, advancing and receding contact angle, contact angle hysteresis and roll-off angle
  • Surface free energy: Sessile drop, captive bubble and meniscus methods
  • Surface- and interfacial tension: Pendant drop and reverse pendant drop methods
  • Roughness-corrected contact angle and 3D surface roughness: Fringe projection phase-shifting method
  • Interfacial dilatational rheology: Pulsating drop method
  • Demonstration video
  • Benefits
  • Applications
  • Accessories
  • Theta range comparisons

Demonstration video


One instrument for all needs

  • Fully automated system from droplet creation, placement and sample movement. Easy to use touch display for faster measurement setup.
  • Image quality enhancement with Autofocus, 5MP camera, DropletPlus technology and environmental sensors.
  • Electronic camera tilt and level indicator for improved accuracy and traceability.
  • Single, double or multi liquid dispenser option for Surface Free Energy analysis.
  • Select ready-made experiments or create custom programs.
  • Automatic baseline detection and drop shape fitting.
  • Monochromatic cold LED light source for reduced sample evaporation.
  • Contact angle on curved surfaces, circular and near-circular.
  • The effect of roughness to wettability can be measured with the unique 3D Topography module.


  • Contact Angle Measurements on Single Fibres
  • Tensiometry in Inkjet Printing Applications
  • Self-Cleaning Coatings
  • Influence of Contact Angles and Surface Free Energies on Biocompatibility of Biomaterials
  • Wettability of Pharmaceutical Powders
  • Dynamic Contact Angles on Super hydrophobic Surfaces
  • Pulsating Drop Technique to Characterise Surfactant Behaviour in Flotation Process
  • Contact Angle Measurement for Surface Treatment Evaluation in Packaging Industry
  • CO 2 in Enhanced Oil Recovery
  • Comparison of Theta QC and Dyne Pens for Quality Control Applications
  • Contact Angle Measurements in Solar Cell Industry
  • Contact Angle Measurements for Microfluidic Chips
  • Adhesion to Wood-Plastic Composites
  • Influence of Topography and Wettability on Biocompatibility


3D Topography module

This option enables 3D surface roughness and contact angle to be measured on exactly the same sample location.

The roughness corrected contact angle makes it possible to understand the influence of surface roughness and chemical modification separately on wetting and adhesion properties.

Applications include the biocompatibility of implants and wettability of paper coatings.



Theta High Pressure Chamber

This module enables interfacial tension and contact angle measurements at high pressures and temperatures.

Applications include Enhanced Oil Recovery (EOR) to provide a quantitative measure of wettability in oil reservoirs and to understand the properties of Polymers.



Pulsating Drop module

The module functions by oscillating drops with control of frequency, amplitude and wave shape. This easy measurement of interfacial rheology provides viscoelasticity information for surfactant applications.






Picoliter Dispenser


This allows precision measurements with low volume drops as small as 20 pl. Applications include inkjet printing, printed electronics and contact angle measurement of a picodrop deposited on single fibre.




Tilting Cradle

This tilts the entire Theta and allows automated measurements of dynamic contact angle, used as an indicator of surface homogeneity. Advancing and receding contact angles are measured at the exact moment the drop on the surface starts moving.


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Theta range comparisons

Available measurements Theta Flow Theta Flex Theta Lite
Static contact angle and captive bubble
Batch contact angle
Dynamic contact angle
Menisuc contact angle
Surface/interfacial  tension
3D surface roughness and roughness-corrected contact angle
Interfacial rheology
Surface free energy Zisman Plot, OWRK/Extended Fowkes, van Oss Acid-Base, Wu, Neumann’s Eq. of State, Schultz 1 and 2

Product Enquiry


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