Hemp could hold the key to improving paper-based analytical testing devices

Hemp could hold the key to improving paper-based analytical testing devices

Hemp is one of the most versatile crops people can grow, and it is finding its way into nearly every industry. Now, analytical testing devices can be added to the long list of products that can be made with hemp.

A recent study conducted by researchers from Turkey and the United States found that hemp could replace trees in paper-based diagnostic products.

Why the type of paper matters

Microfluidic analytical devices reportedly are used in point-of-care diagnosis, clinical tests, food safety measurements and environmental protection. They work by wicking up a liquid that is channeled with water-resistant barriers to specific areas. Once the liquid reached the intended area, a measurable reaction occurs.

Microfluidic paper-based analytical devices have been in use since 2007, although they build upon a long history of paper-based diagnostic products, such as pregnancy tests, pH tests and paper chromatography.

They provide practical testing options in many fields because they are affordable and portable. Unlike other types of testing, they do not require specialized labs or lab equipment, which adds to the appeal.

Making these products out of hemp instead of trees is beneficial because hemp requires less water to process into paper and makes it possible to sell the products at a lower price point.

According to a recent Cannabis Tech article, one acre of hemp produces four times the amount of fiber pulp than an acre of trees. A recent study from Cambridge University even found that a field of hemp is roughly twice as effective at capturing atmospheric carbon as forests are. This means that switching to hemp in these products could benefit both the environment and the consumers.

‘Hemp has the strongest natural fiber’

Although the recent study found that hemp paper is a good alternative to the tree paper currently used in these products, there are differences between the two types of paper.

Different types of paper have different characteristics, which can include flow rate, porosity and particle retention. The qualities of a particular type of paper can affect the types of applications it is best suited for.

The National Hemp Association reports that one of the most notable characteristics of hemp paper is its strength. It is reportedly stronger than wood paper and can be folded more times without tearing than wood-based paper can.

“[H]emp has the strongest natural fiber of any source,” according to the National Hemp Association.

This means that in addition to the environmental and financial benefits, hemp-based diagnostic devices could potentially perform better than tree paper in harsh environmental conditions.

How hemp paper measured up in the study

The recent research into the viability of hemp-based paper in analytical devices involved testing several properties of hemp paper. Researchers used a desktop pen plotter and commercial markers to create water-resistant barriers on the paper. They tried to determine how small of water resistant patterns they could make on the paper.

Then they examined how quickly the paper wicked up different liquids and how far the fluids traveled on the paper. Researchers later used hemp-based testing devices to measure the potassium levels in artificial urine.

According to the published study, “The main drawbacks of hemp-based fibers and composites, or biocomposites in general, are poor adhesion to synthetic polymers, degradation during curing at high temperatures, and humidity absorption, resulting in weaker mechanical properties compared to synthetic materials.”

The study found that hemp paper is a good alternative for low-viscosity fluids, such as urine. However, it took the hemp fibers longer to wick up liquids with thicker consistencies.

Researchers reportedly suggested using origami, adhesives or high-resolution patterning to help counter this potential problem. Still, more studies will need to be conducted before hemp-based testing devices make their debut on the market.


[1] https://www.cannabistech.com/articles/what-are-hemp-based-microfluidics/

[2] https://www.mdpi.com/2072-666X/12/2/182/htm

[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6209828/

[4] https://www.dezeen.com/2021/06/30/carbon-sequestering-hemp-darshil-shah-interview/

[5] https://nationalhempassociation.org/facts-statistics-hemp/

[6] https://www.sciencedirect.com/science/article/pii/S0167931718305069