The instrument has a 1-year warranty with the exclusion of consumables (i.e. syringe, needle, batteries). Phone warranty is up to the device manufacturer (Motorola). It is currently 1-year on the phone model included in the package.

Yes! We include free software updates for your device lifetime (5 Years).

We suggest using the flow rate of 1-2 ul/s. One rotation of the syringe plunger included in the package means 5ul. You can calculate the rotating speed based on this value.

Young-Laplace Method

• This method uses the whole drop profile to calculate the contact angle value.
• This method is only compatible with an axisymmetric drop, which is only sometimes seen in practice because a needle is typically inserted into the drop to increase or decrease the drop volume.
• This method’s measurement results are more consistent compared to the polynomial fitting method.

Polynomial Method

• This method uses only a certain percentage of the drop profile to calculate the contact angle value.
• This method is compatible with both axisymmetric and non-axisymmetric drops.
• The measurement results of this method are less consistent, as local surface imperfections affect them.

We provide a bubble level to level the stage. You need the image calibration number (outer diameter of the needle) and the gravity if you are using Yonge-Laplace method for measurement. You do not need to do any calibration for the Polynomial fitting method. No other calibration is needed.

In the standard version, the drops will be generated manually. We include a threaded plunger syringe from Hamilton in the package. Additionally, for the sliding angle measurement, the tilting of the stage will be manual.

In the automatic version, you can generate the drop with a set volume and the flow rate. Additionally, for the sliding angle measurement you can choose the tilting rate and angle. Everything else apart from these 2 components is the same.

Check out our Unboxing video to understand what you will receive in the package.

Yes! You only need to purchase the updated phone model. We will provide compatible apps for the new phone model free of cost.

For accuracy purposes, we are restricted to using Motorola Stylus phone or an iPhone (iOS 15 or above) as we need access to raw images to best utilize our image processing algorithms. If you have access to either of the phones, we will simply give you the rest of the setup at a reduced price. 

Yes! Once the app is activated, it does not require an internet connection to work.

We can capture multiple images and play it back as a video.

10 frames per second

We have a one-size, syringe holder currently for the size of Hamilton syringe we ship in the package. If you need it to be wider, just let us know what size you need and we can custom design one per your requirements.

Yes!

Yes! We can do Interfacial Tension Measurement between two immiscible liquids using pendant drop method in our Surface tension module.

These three methods are the most widely used methods to calculate the solid surface energy. Any of them can calculate the solid surface energy for you. However, the literature suggests that depending on the type of surface you want to do the measurement for, one/ two of these methods may perform better than others. So, we suggest that you first check what method is most widely used for your sample in the literature and select the same when you do your measurement.

• Neumann method: This method involves use of only One Liquid.
• Fowkes Method: This method involves use of Two Liquids (1 purely Dispersive liquid and 1 polar liquid)
• Oss & Good method: This method involves use of Three Liquids (1 Dispersive liquid, 1 Acid, 1 Base)

• The best results for the pendant drop methods come when the droplet is at the cusp of detaching from the capillary. At this point, the droplet is significantly “deformed”; taking a raindrop-like shape.
• This is because the surface tension of the droplet is trying to resist the force of gravity stretching the droplet. Thus, when the droplet is significantly deformed, surface tension is pushed to its limits. measuring the surface tension here will give the best results.
• The best approach for generating a well deformed drop is:

  1. Slowly increase the volume and remember the shape of the drop just before the drop detaches from the needle.
  2. Generate a second drop with the similar shape as the last one before detaching.

• The criterion deciding the volume is whether the liquid drop is well deformed (not a spherical shape). 
• Generally, a larger needle will help with this. We suggest using a flat head needle with a diameter larger than 1.75mm.
• Also, be as accurate with the image calibration number (measurement of the outside diameter of the needle) as possible.
• Capture the images quickly after the droplet is generated, to avoid contamination as the droplet is suspended in air.

• Practical surfaces and coatings naturally show contact angle hysteresis, indicating a range of equilibrium values. 
• Measuring static contact angles provides a single value within this range. 
• Solely relying on static measurements poses problems, like poor repeatability and incomplete surface assessment regarding adhesion, cleanliness, roughness, and homogeneity.
• Practical applications require understanding a surface’s liquid spreading ease (advancing angle) and removal ease (receding angle), such as in painting and cleaning. 
• Measuring advancing and receding angles offers a holistic view of liquid-solid interaction, unlike static measurements, which yield an arbitrary value within the range. Hence, we recommend doing Advancing and receding contact angle measurements.