## 1 Introduction  
Internal combustion engines (ICEs) have been the dominant power source for automotive applications over the centuries. A relentless pursuit of efficiency and performance has marked the evolution of ICEs over the years [1]. One critical component in optimizing the performance of an internal combustion engine is the idle air control device/actuator, which controls the engine's air inlet and maintains optimal combustion characteristics during idle conditions. A well-performed idle air control actuator contributes to smoother idling and plays a significant role in fuel economy, emission reduction, and overall engine idling performance. Nowadays, researchers are interested in developing automotive engine actuators using quick response, weightless, and controlled materials like shape memory alloy (SMA) materials to offer a potential solution to the challenges associated with mechanical or traditional actuators. Traditional idle air control valves utilize electromagnetic actuators or stepper motors. They have served their purpose well but face limitations of response time, complexity, and electric energy consumption. Shape memory alloys (SMAs) are unique smart materials that can regain their original shape when subjected to a specific thermal stimulus, such as heat [2, 3]. This property has been harnessed in various engineering applications, from biomedical to aerospace actuators. SMAs are classified into different categories based on the alloying types but the most widely known and used is Nickel Titanium (NiTi) Shape Memory Alloy, known as Nitinol. Its shape memory effect (SME) and superelasticity make it suitable for various applications, including in the automotive sector. NiTi shape memory alloys are available on the market in different forms including cold-rolled strips and tubes [4; 5; 6], wires [7; 8], sheets or plates [9; 10], foils [11; 12], and springs [10; 13; 14]. In different complicated actuators that use composite materials, shape memory alloy wires are embedded in the composite to improve their working ability, such as fast response in shape-changing of the structure, mechanical behaviour, and impactful actuation [15; 16]. They are used in automotive applications but many are also widely applied in robotic systems [17; 18]. The shape memory alloys in the tube form operate at higher temperatures than their wired counterparts [19]. The hollow form of the tube provides the cooling channel of these shape memory alloy-based actuators [19; 20]. The cooling time of SMA is reduced and the life span of the actuators increases. Plate-based shape memory alloys are used in aerospace actuators for the vibration and stiffness control of flexible structures [21]. In the automotive industry, they are applied in adaptive shock control actuators [22; 23]. The actuators with improved stroke and fast actuation responses use spring-based shape memory alloys [13; 24]. SMA spring actuators are mostly applied in the automotive sector. They perform at the constant strain within many actuation cycles and can be deformed up to 200% of their length with low mechanical loads [25; 26]. Moreover, the coil spring increases the amount of restoring energy to reduce the consumed energy during actuator operation. An actuator can have two SMA springs or a wire and spring combination, but one element serves as a biasing material [27]. Several researchers are interested in working on SMAs for automotive applications to modernise actuators in this sector. They are used to simulate or experiment to find the results of a proposed designed actuator. None have been used to evaluate their operability in the complete system, which represents the innovation of this work. [PERSON] et al. [28] used a shape memory alloy with a Nitinol type to design and control a variable exhaust nozzle actuator. The configuration has SMA wire and a bias spring, but the area is reduced by 40% from the existing mechanical one. [PERSON] et al. [29] proposed an emergency brake using an SMA material in its operation.