- 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
What you can measure
Widen your view
This 3-minute video will provide you with all you need to know about Theta Flex. Watch the video in fullscreen for the best experience.
3 reasons to invest
One instrument for all your needs
Flexible at its core, this instrument gives you plenty of measuring possibilities. All neatly packed in our easy-to-use software. Add accessories and modules to match your needs.
Results you can trust
We know that high quality imaging is essential for high quality results. Therefore the Theta Flex camera has a resolution of 1984 × 1264 px with a maximum of 3009 FPS. Sophisticated algorithms record and analyze the contact angle and surface free energy for you, and you can follow the experiment in real-time.
Need for speed?
All steps of your measurements can be automated to speed things up in the lab. This way you can also avoid user dependency. The outcome will be more precise, and experimenting more smooth. Enjoy.

Attension Theta Flex
An award-winning instrument
Did you know that Attension Theta Flex received a Red Dot for its ground-breaking and intuitive design? Our instrument was elected Best of the best in the category of Industrial design at the Red Dot Award for Product Design 2020, making it a winner in the world’s most renowned design competition.
“Our experienced jury only awards the Red Dot: Best of the Best to the most convincing products in a category. This is why only a small percentage of the objects entered win this award. It is proof that every detail of the design is coherent and well thought through. Consumers can trust our experts’ decision entirely and can rest assured that the products are of top quality.” says Professor Dr. Peter Zec, founder and CEO of Red Dot.
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A closer look
Check out the specifics of Theta Flex and compare it Theta Flow and Theta Lite to find out what you need. Theta Flex systems come in ready-made packages optimized for your automation level. Other packages can also be formed easily thanks to the modular design.
Theta Flow |
Theta Flex |
Theta Lite |
|
Available Measurements |
|||
Static contact angle and captive bubble |
√ |
√ |
√ |
Batch contact angle |
√ |
√ |
√ |
Dynamic contact angle |
√ |
√ |
√ |
Meniscus 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 Equation of State, Schultz 1 and 2 |
||
Software and hardware |
|||
Measuring range (°, mN/m) |
0…180, 0.01…2000 |
0…180, 0.01…2000 | 0…180, 0.01…2000 |
Accuracy (°, mN/m) |
±0.1, ±0.01 |
±0.1, ±0.01 | ±0.1, ±0.01 |
Maximum sample size (mm) |
Unlimited×100×320 |
Unlimited×100×320 (with stage) | Unlimited×45×200 (with stage) |
Integrated sample holders |
√ |
√ |
√ |
Maximum resolution (px) |
2592 x 2048 (5 MP) |
1984 × 1264 (2.3 MP) | 1280 × 1024 (1.3 MP) |
Maximum measuring speed (fps) |
3422 |
3009 | 2068 |
Camera |
CMOS 1'' USB 3.0 digital camera with zoom |
CMOS 2/3'' USB 3.0 digital camera with zoom | CMOS 1/2'' USB 3.0 digital camera with fixed zoom |
Image focusing |
Software-controlled autofocus, manual fine focus in optics |
Manual fine focus in optics | Manual fine focus by optical rail |
Image quality |
Enhanced with DropletPlus technology, Native |
Native | Native |
Camera protection |
Inside instrument covers |
Inside instrument covers | Inside instrument covers |
Camera view angle (°) |
-4 ... 2.5, with digital scale |
-4.5 ... 2.5, with mechanical scale | -2 ... 2 |
Light source and size |
LED based homogeneous background lighting, 62 x 62 mm |
||
Field of view (Ø, mm) |
1.44…45.3 |
1.44…32.3 | 2.9…12 |
Measurement indicator LED |
√ |
√ |
- |
Integrated touch display |
√ |
- |
- |
Environment monitoring |
√ |
- |
- |
Disposable tip dispensing |
√ |
√ |
√ |
Software |
OneAttension, includes all measurement modes |
OneAttension, includes all measurement modes |
OneAttension, includes all measurement modes |
Dimensions — Basic frame (L×W×H, mm) |
765 x 230 x 435 |
765 x 230 x 435 | 495 x 130 x 310 |
Weight — Basic frame (kg) |
29 |
26 | 5 |
Power supply (VAC) |
100...240 |
100...240 | 100…240 |
Frequency (Hz) |
50...60 |
50...60 | 50 ... 60 |
OneAttension Software
We made our software for Theta Flex with you in mind. It is a fine combination of a very intuitive interface and high functionality. Follow your experiment live, and get the results within seconds. OneAttension is analyzing made easy. Let's have a look at the features!
OneAttension Features
- User friendly interface
To get you going in no time - Fully automated measurements
Saving your time and avoiding user dependency - Automatic baseline detection and drop shape fitting
For simplicity and precision - Batch angle mode
When you have plenty of tests to run in no time - Meniscus contact angle mode
When you are finding out the contact angle of fibers - Automated liquid purity checkup
So you can trust your results - Fully automatic dynamic contact angle mode with the needle method
For user-independent results
Wetting and Adhesion analysis is now part of the all-inclusive OneAttension software!
Add more possibilities
With the modular design and an extensive range of modules and accessories you have room to upgrade or change the Attension Theta Flex as your needs evolve. Have a look at a few selected examples or explore the full range below.

Topography 3D module
Theta Flex can be combined with the unique 3D Topography module that takes the wettability and adhesion analysis into a completely new level by measuring both contact angle and surface roughness of the sample in a single measurement. Distinguish the effect of roughness on contact angle and surface free energy.

High Pressure Chamber
The High Pressure Chamber is designed for wettability research within enhanced oil recovery and enables measurements at pressures up to 400 bars and temperatures up to 200°C. Integrated chamber piston and sample port are optimized for the best usability and versatility.

Tilting cradle
A software controlled tilting cradle. Used for studying dynamic contact angles. Tilting range from 0 to 90° and tilting resolution 0.1°. The vacuum stage top C204B is recommended to be used with this option.

Pulsating Drop Module - PD200
Software controlled drop size pulsing for interfacial rheology measurement of viscoelastic properties of interfacial layers at liquid-air or liquid-liquid interfaces.

Picoliter Dispenser
Automated picoliter-scale drop formation. Especially for inkjet applications and for measuring contact angle on very small sample areas.
What others say
Our instruments are present at many prestigious universities and research facilities world wide. Take a minute to find out what others say about Theta Flex.
Dr. Nicola J. Irwin. Queen’s University Belfast
"The ability to accurately measure contact angle as a measure of surface wettability is of utmost importance as we develop new technologies to prevent medical device-associated issues of infection and tissue trauma. The ease-of-use of the instrument and associated software is a major advantage and the support offered by the team, particularly with new applications, is exceptional.”

Queen’s University Belfast
This prestigious university in Northern Ireland is ranked amongst the top 200 in the world. Dr. Nicola J. Irwin, Lecturer in Pharmaceutical Materials Science School of Pharmacy, has been using our instrument in her work.
Ville Jokinen. Aalto University
"The ability to measure the advancing and receding contact angles with a single click and having the data into a convenient format saves time and reduces the human error."
Watch the full story

Aalto University, Finland
Aalto University is a top Finnish university combining science, technology and arts into a collaborative environment for both scientific communities and companies. Our contact angle meters and tensiometers have been used there in research for decades.
Researcher at MIT
“The reproducibility of the measurements acquired is excellent even with the lowest surface energy values and the tensiometers are quite flexible with regards to sample size. The software is also very useful and the customer support for the products is excellent.”

MIT, USA
MIT, Massachusetts Institute of Technology, is a world-leading research university with a mission to advance knowledge and educate students in science and technology. MIT use our tensiometers to study contact angles and interfacial energy.
Learn more
We have gathered all our in-depth knowledge associated with Theta Flex. Browse around amongst webinars, overviews and videos to find a topic of your interest.
- Attension

The Importance of Contact Angle in Industry
- Attension

Contact Angle Hysteresis and the Roll-off Angle with Tilting Method
- Attension

Automated Dynamic Contact Angle Measurement with Needle Method
- Attension

Effect of Wettability in Biomedical Applications
- Attension

The Influence of Surface Roughness on Wettability
- Attension

Superhydrophobic Surfaces - From Lab to Real Life Applications
- Attension

Enhanced Oil Recovery - Measuring Minimum Miscibility Pressure
- Attension

Surface and Interfacial Tension
- Attension

Wettability Alteration in Carbonate Reservoir
- Attension

Enhanced Oil Recovery using Nanoparticles
- Attension

How do Pressure and Temperature Affect on Wettability?
- Attension

Wettability Measurements for Enhanced Oil Recovery Optimization
- Attension

A Prove of Superior Coating Quality by Dynamic Contact Angle Measurement
- Attension

Effect of Temperature and Pressure on Wettability of Solids
- Attension

How to Measure Superhydrophobic Surfaces in Practice?
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CO2-in-water Foam
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Surface Free Energy Methods
- Attension

The Importance of Surface Tension in Industry
- Attension

Contact Angle - What is it and how do you measure it?
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Surface Free Energy - What is it and how to measure it?
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Surface Free Energy in Practice
- Attension

Wettability of Contact Lenses
- Attension

Surface and Interfacial Tension
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Determination of Optimal Plasma Treatment Time of Polypropylene
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Why Interfacial Rheology is Important
- Attension

Surface Tension and Surfactants in Industrial Processes
- Attension

Using Contact Angle Measurements in Surface Research and Quality Control
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Wettability Measurements in Biomedical Applications
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Characterizing Water Repellency with Dynamic Contact Angles
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Evaluation of Biomedical Coatings with Contact Angle Measurement
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Interfacial Rheology as Emulsion and Foam Stability Indicator
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Surface Evaluation for Good Wettability and Coating Adhesion
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Adhesion - How to Use Contact Angle to Predict Adhesion and Bonding
- Attension

Contact Angle Measurements in Electronics
- Attension
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Characterization and analysis of hydrophobicity, interfacial tension and contact angle of acetyl TAG used for various food applications
- Attension

Superhydrophobic and Superhydrophilic Surfaces for Cell Trapping
- Attension

Probing Lipid Monolayers with Pendant Drops From Surface Pressure Isotherms to Interfacial Rheology
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