A textile patch antenna is an attractive package for wearable applications as it offers flexibility, less weight, easy integration into the garment and better comfort to the wearer. When it comes to wearability, above all, comfort comes ahead of the rest of the properties. The air permeability and the water vapor permeability of textiles are linked to the thermophysiological comfort of the wearer as they help to improve the breathability of textiles. This paper includes the construction of a breathable textile rectangular ring microstrip patch antenna with improved water vapor permeability. A selection of high air permeable conductive fabrics and 3-dimensional knitted spacer dielectric substrates was made to ensure better water vapor permeability of the breathable textile rectangular ring microstrip patch antenna. To further improve the water vapor permeability of the breathable textile rectangular ring microstrip patch antenna, a novel approach of inserting a large number of small-sized holes of 1 mm diameter in the conductive layers (the patch and the ground plane) of the antenna was adopted. Besides this, the insertion of a large number of small-sized holes improved the flexibility of the rectangular ring microstrip patch antenna. The result was a breathable perforated (with small-sized holes) textile rectangular ring microstrip patch antenna with the water vapor permeability as high as 5296.70 g/m² per day, an air permeability as high as 510 mm/s, and with radiation gains being 4.2 dBi and 5.4 dBi in the E-plane and H-plane, respectively. The antenna was designed to resonate for the Industrial, Scientific and Medical band at a specific 2.45 GHz frequency.

The manuscript presents a novel approach to designing and fabricating a stretchable patch antenna designed for strain sensing and the wireless communication of sensing data at the same time. The challenge lies in combining flexible and stretchable textile materials with different physical morphologies, which can hinder the adhesion among multiple layers when stacked up, resisting the overall stretchability of the antenna. The proposed antenna design overcomes this challenge by incorporating a lattice hinge pattern into the non-stretchable conductive e-textile, transforming it into a stretchable structure. The innovative design includes longitudinal cuts inserted in both the patch and the ground plane of the antenna, allowing it to stretch along in the perpendicular direction. Implementing the lattice hinge pattern over the conductive layers of the proposed patch antenna, in combination with a 2 mm thick Polydimethylsiloxane (PDMS) substrate, achieves a maximum of 25% stretchability compared to its counterpart antenna without a lattice hinge design. The stretchable textile antenna resonates around a frequency of 2.45 GHz and exhibits a linear resonant frequency shift when strained up to 25%. This characteristic makes it suitable for use as a strain sensor. Additionally, the lattice hinge design enhances the conformability and flexibility of the antenna compared to that of a solid patch antenna. The realized antenna gains in the E and H-plane are measured as 2.21 dBi and 2.34 dBi, respectively. Overall, the presented design offers a simple and effective solution for fabricating a stretchable textile patch antenna for normal use or as a sensing element, opening up possibilities for applications in the communication and sensing fields.

Crimp, also known as fabric waviness, is a key factor affecting weaving efficiency and the performance characteristics of woven fabrics, especially high-performance fabrics. Increased crimp typically enhances yarn interlocking, thereby improving the structural stability of the fabric. The added friction between yarns boosts resistance to distortion and slippage, which is crucial for maintaining the fabric's shape during use and subsequent processing. However, excessive crimp can reduce the mechanical symmetry of the fabric and, in demanding applications such as composite materials, compromise its dimensional stability under stress. Producing composite preforms with minimal crimp while ensuring improved structural integrity remains a significant challenge. Crimp levels can be adjusted by employing different weave patterns while keeping the fabric-making parameters constant. In high-performance applications like composites, the reduced crimp is preferred for better load distribution and material strength, making non-crimp woven textiles a favorable option. Advanced automated processes are typically employed to produce non-crimp woven preforms, including three-dimensional (3D) woven preforms with three sets of interlocked yarns or uni-directional woven preforms. This research uses conventional two-dimensional (2D) weaving techniques to fabricate high-performance composite materials. Experimental studies were conducted on various basic weave patterns to produce high-performance carbon woven preforms using advanced 2D weaving machines (Dobby shedding). The findings demonstrate that the weave design significantly influences the crimp in carbon woven preforms. The crimp percentage (C%) was calculated as the ratio of the un-crimped length of the tow to its crimped length. The study revealed that the crimp in both warp and weft tows of the woven preform varies notably based on the weave design.

The manuscript presents a novel approach to designing and fabricating a stretchable patch antenna designed for strain sensing and wireless communication of sensing data at the same time. The challenge lies in combining flexible and stretchable textile materials with different physical mor-phologies, which can hinder adhesion among multiple layers when stacked up, resisting the overall stretchability of the antenna. The proposed antenna design overcomes this challenge by incorpo-rating a lattice hinge pattern in the non-stretchable conductive e-textile, transforming it into a stretchable structure. The innovative design includes the longitudinal cuts inserted in both the patch and the ground plane of the antenna, allowing it to stretch along in the perpendicular direction. Implementing the lattice hinge pattern over the conductive layers of the proposed patch antenna in combination with a 2 mm thick Polydimethylsiloxane (PDMS) substrate achieves a maximum of 25% stretchability compared to its counterpart antenna without lattice hinge design. The stretchable textile antenna resonates around a frequency of 2.45 GHz and exhibits a linear resonant frequency shift when strained up to 25%. This characteristic makes it suitable for use as a strain sensor. Ad-ditionally, the lattice hinge design enhances the conformability and flexibility of the antenna compared to a solid patch antenna. The realized antenna gains in the E and H-plane were measured as 2.21 dBi and 2.34 dBi, respectively. Overall, the presented design offers a simple and effective solution for fabricating a stretchable textile patch antenna for normal use or as a sensing element, opening up possibilities for applications in communication and sensing fields.