BIELMEIER | CONSULTING
MECHANICAL ENGINEERING & DESIGN
TEXTILES
Insect-Bite Resistant Fabrics
Innovations in
Chemical-free, insect resistant protection (ChIRP)
fabrics and garments
The fabrics we wear everyday CAN help stop insect bites, but many customers are unaware of a garment’s insect-bite protection. News reports of Zika and Lyme disease outbreaks in the southern US has raised customer awareness of the potential diseases carried by mosquitos and ticks. However, consumers are increasingly averse to spraying themselves and young children with toxic insecticides. A standardized insect-resistant fabric (IRF) rating system, similar to the UPF system, is needed to better inform customers and garment manufactures.
In 2017, I created the micro-penetrator puncture test (Micro-PPT), which can be used to measure the physical mosquito-bite resistance of a particular fabric architecture (weave, material, twist…). The quick and inexpensive test method was designed, fabricated and validated using US army funding and can be used to rank the bite protection probability of fabrics and thin films. Currently, fabrics used in military uniforms have been tested/ranked, and future testing will include consumer fabrics and thin film. In addition, testing will be extended to simulate biting of other arthropods such as ticks, chiggers, flies, and scorpions.
Micro-PPT designed for puncture testing of fabric to measure mosquito-bite resistance of fabrics.
Glass needle with diameter of a mosquito proboscis to test resistance of military uniform fabric to insect biting.
Insect-Resistant Fabric (IRF) Rating System
Currently, I am a researcher at Boston University and creating a new standardized insect-resistant fabric (IRF) rating system. BU has several state-of-the-art laboratories that are ideal for testing fabrics. The IRF will be similar to the similar to the UPF system for measure ultraviolet light protection of fabrics. The IRF is needed to better inform customers and garment manufactures.
New fabric weaves for uniforms & personal protection equipment
We are innovating chemical-free insect resistant protective (ChIRP) clothes and apparel for governmental and commercial applications. Working with leading researchers at BU, I am developing new fabrics for the development of flexible breathable garments that can be worn for all day protection. These ChIRP fabrics are being incorporated into a children clothing line called Lil Buggers and sold at www.lilbuggersgear.com.
Micro-penetrator puncture testing (Micro-PPT)
The bite resistance of these new fabric architectures will be evaluated using the novel micro-penetration puncture test (Micro-PPT), which was developed to measure the physical resistance of fabrics to mosquito-bite-sized punctures. Until recently, the US Military compared a fabric’s resistance to insect-biting by a live-mosquito blood-feed test, which is costly, time-consuming, and produces data with a wide variance [3]. However, the Micro-PPT is quick and inexpensive, and therefore a wide range of fabrics architectures and garments can be tested for different types of arthropod bites. The Micro-PPT was developed by Bielmeier and funded by the US Army Natick Soldier Systems Center and UMASS Lowell in 2017. The Micro-PPT uses a glass rod of similar size and shape as a mosquito’s proboscis to puncture fabric and measures puncture forces (Figure 5). Mosquito proboscis punctures human skin at forces below ~18 mN [22]. During testing, fabric is held in a stretched condition, which is most vulnerable to insect biting [23]. The micro-protection probability, Pµ, of many fabrics or thin films can be calculated from the results of the Micro-PPT [24]. Table 1 shows a fabric’s Pµ value and protection ranking for six selected military fabrics. The Micro-PPT was validated using thirteen military uniform fabrics and compared to live-mosquito blood-feed test data collected by US Army Natick Soldier Systems Center. This proposed research will extend the capabilities of the Micro-PPT to capture bite forces of other arthropods, such as ticks, chiggers, and scorpions.
Micro-PPT Testing to Simulate Insect Biting
Insect-resistance for 6 fabrics
My Channel
Fiber movement during puncture with a sphere. Lines represent fiber location only and do not represent fiber width.
Fabric Architecture design images.
Micro-model image of a mosquito proboscis puncturing a section of plain weave fabric.
Force & displacement profile of a quasi-static puncture of fabric with key points identified.
Finite Element Modeling & Impact Resistance Modeling of Fabrics
I have a decade of experience using finite element analysis (FEA) of composite and homogeneous materials for aerospace and military applications. I have conducted conducted FEA at the assembly, component and material levels for predicting failure criteria & reducing component weight. I have analyzed components on the NASA HELIOS Pathfinder HALE ROA, NASA Mars Flyer, & InstantEye UAV.
The focus of my doctoral disseration was the creation of micro-models that describe the architecture of woven fabrics to develop flexible textile-based personal protection equipment (PPE) to resist puncture by penetrators ranging from knives to micro-needles. I developed a modeling method that utilized Digital Fabric Mechanical Analyzer (DFMA), a new FEA software, for application of measuring impact & puncture resistance of woven fabrics. The efficiency, stability & accuracy of DFMA were compared with traditional modeling software (ABAQUS). Leveraged cluster computing to increase model efficiency and wrote MATLAB script to visualize fiber movement during penetration with a micro-penetrator. Published journal articles on micro-model study of textiles resistance to micro-penetrators (mosquito proboscis & sewing needles).
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Modeling at the fiber, yarn & fabric level
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FEA analysis for assessing component failure or optimizing design weight/strength
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Fabric development for the use of textile-based personal protection equipment (PPE)