# Electrospinning of High-Performance Nanofibres: State of the Art and Insights into the Path Forward
## 4 Discussion
### Challenges, Limitations, and Avenues of Solutions
#### 4.2.1 Standardized Characterization Methods
Some alternatives to the universal mechanical tester have been reported for the mechanical characterization of nanofibrous membranes. For example, the Kawabata Evaluation System (KES) has been used to characterize the mechanical properties of m-aramid nanofibrous membranes [11; 47; 67]. Moreover, machines designated for testing conventional microfibres have been employed to assess the strength of nanofibrous membranes [7]. The lower load cells on these machines may allow greater accuracy in terms of results. However, a major limitation of measuring the mechanical strength of nanofibres is that this low-force range testing equipment is not as widely available as universal tensile testing machines. In general, there is a need for testing and analysis methods that consider nanofibrous materials as unique, as opposed to the adaptation of standards intended for plastics. However, since such a standard does not yet exist, reference to other standards can help provide sufficient detail on specimen preparation and testing procedures in an organized manner. The adaptation of an existing standard would also help gain consistency in which test parameters are reported. Key elements of the tensile tests, including ambient conditions, load cell capacity and precision, and test frame configuration are also often omitted from reports of results, making replicability between research groups increasingly difficult. As a result, only comparisons of the mechanical behaviours of fibres and materials produced within a given article are typically possible. The use of a standardized method to assess the mechanical performance of the nanofibres may help gain a more complete understanding of the effects of electrospinning parameters on the mechanical strength of the nanofibres by allowing for a comparison of the strengths of nanofibres produced by various research groups. The development of standardized test methods for assessing the performance of nanofibrous materials will be necessary to encourage collective progress within the field. Not only will these methods eliminate inconsistencies between studies, but they will also allow for the comparison of performance between high-performance nanofibres. To date, studies on the electrospinningning of high-performance nanofibres tend to compare the performance to micro-scale counterparts or to nanofibres electrospun from conventional polymers. Other comparisons between high-performance nanofibres will be a useful tool as the research progresses toward direct applications and industrialization. The shared properties of these fibres such as high strength, heat resistance, and chemical resistance mean that they may have overlaps in terms of applications. However, without a method to compare their performance, the best choice of high-performance polymer may be made based on the ease of electrospinningning or the existence of test results for a specific application. Increasing standardization will help decide the most suitable polymer in terms of performance for specific applications.