State of the art baby strollers The current work is an attempt to design and fabricate an ergonomic baby stroller with the latest state of the art features. A review on the design of baby strollers in the previous years was done ranging from the year 1980 to 2014. Based on the review it was found out that the idea of a foldable frame emerged since the early 1980s where people started to prioritize space saving. The use of electronics devices in strollers has not been properly implemented due to the bulkiness of the battery and the clutter mess of wires. Infant's safety and comfort has always been the number one priority by designing a seat that is contoured to a baby's spine, ultimately making baby's growth much safer. In lieu of the current work, a harmonious prototype design was fabricated using Rapid Prototyping system. The idea was to fuse the usage of electronics with the stroller by inventing modular "plug and play" attachment devices that provide customizability to baby strollers which include headlights and cooling fan attachments. Besides that, the latest state of the art designs of the ergonomic baby stroller such as a ventilated back rest, on-board rocking baby chair, bidirectional push handle with ergonomic grip support, frame with integrated hooks for storing different types of "plug and play" attachments and hooks for attaching the foldable stroller to a typical standard shopping cart were implemented. Baby strollers are increasingly popular among the generations of baby boomers. Despite the popularity, the state of innovations in the design of baby strollers has plateaued in recent years. This article illustrates the evolution of the design of baby strollers from the year 1980 to 2014. Based on the review, it was found out that the idea of a foldable frame emerged since the early 1980s where users started to prioritize space saving. The use of electronics devices in strollers has not been properly implemented due to the bulkiness of the battery and the clutter mess of wires. In lieu of the current work, the idea was to fuse the usage of electronics with the 3 in 1 stroller by inventing modular "plug and play" attachment devices that provide customizability to baby strollers that include headlights and cooling fan attachments. The possibilities of various types of attachments will be endless. There is significant design knowledge of baby strollers since 1980 to 2014, in which, is reviewed to identify flaws and advantages of each design. There are many methods used to transport babies around and it varies among different cultures and countries. The idea of infant transportation emerges as multitasking and convenience becomes a necessity in parent's everyday lives. Having an infant transportation made it easier for parents as babies are no longer needed to be carried by the parents or sit on top of their parents' back. Babies that are lacking the ability to support their head still and upright are usually carried with slings. Cradleboards are popular among Native Americans to keep babies secure and comfortable (Garrett, McElroy, & Staines, 2002). The early stroller was developed by William Kent in 1733. William Kent designed the pockit stroller to be clam shaped and it was richly decorated and meant to be driven by a small animal such as a goat. Benjamin Potter Crandall saw the potential of this and was the first person in America to sell baby strollers commercially in 1830s. His son, Jesse Armour Crandall further improves the design by adding brake to carriages, designing a frame that is foldable, and a frame that receives devices such as an umbrella (Amato, 2004). Baby strollers that were built in the old days were usually made of wood and wicker with brass joint as seen in Figure 1. Those strollers are sometimes heavily decorated with carvings making it as a canvas for the work of art. Baby strollers then are usually named after a royal family such as Balmoral. In 1889, William Richardson design the first reversible baby stroller where the pusher can choose to face the baby or to face away from the baby. In order for this to be possible, the seat of the stroller is reversible. Richardson designed each wheel to move separately so the stroller can be easily be maneuvered. In 1920, prams are very popular with the advantage of larger wheels and the implementations of braking system into prams. The prams are deeper so the baby will have difficulty to climb out. The frame is also sturdier, lighter, and safer thanks to the improvement of designs over the years (Amato, 2004; Wall-Scheffler, Geiger, & Steudel-Numbers, 2007). In 1965, Owen Maclaren designed a light stroller where light material such aluminium is used as the frame. His design was then mass produced and more light strollers are available for people worldwide (Wall-Scheffler et al., 2007). In 1970, a more basic baby strollers was preferred that has a detachable seat (Amato, 2004; Wall-Scheffler et al., 2007). The design as seen in Figure 2(a) is invented by Kenzo Kassai. The baby stroller can be collapsed down but increases the size length forward. The stroller has a handle which can be pivoted to change the direction, either forward facing position or a back facing position with respect to the baby sitting in the stroller or carriage (Kassai, 1980). Forward facing push type is where the person pushes the carriage is facing the back of the baby in the stroller, and the back facing push type is where the person pushes the carriage views the face of the baby (Kassai, 1980). Figure 2(b) shows a design by Shinroku Nakao, Kouchi Kobayashi, and Kazao Moriya. It is stated as an ornamental design which similar to any other stroller in terms of practicality, but visually appealing (University of Cambridge, 2015). The design consists of a fixed chair, with a canopy that folds outwards. The front wheels have no rotating mechanism, which makes maneuvering a little less convenient (Nakao, Kobayashi, & Moriya, 1980). The invention presented in Figure 3(a), by Henry Fleischer shows a collapsible frame travel stroller. The collapsible frame uses slider slots and pin joint mechanism. The handle can be rotated to suit the user. The handle also pivots forward, which doubles as a mechanism to engage the folding action. The wheels are not rotatable and use simple axel to keep the wheels in place (Fleischer, 1981). As seen in Figure 3(b), the stroller design made by John P. Ettridge has a lower seat position where the toddler facing forward. The handle, seat, frame and undercarriage are interconnected by a linkage so that the components fold down towards the wheels as the wheels move towards each other (Ettridge, 1981). The design also has a footrest for the toddler. The design has a locking mechanism which keeps the stroller erected. The locking mechanism is conveniently placed at reachable height when standing. The stroller in Figure 4(a) has an adjustable backrest collapsible stroller that has a stroller frame formed in two matched side half-frames each whereof comprises three tubular elements, constituting respectively a rear leg, front leg and a stroller pushing arm. It was designed by Pietro Giordani. The construction of baby strollers of the collapsible or fold down type having an adjustable backrest (Giordani, 1982). Figure 4(b) shows a mechanism for adjusting the height of the handles of a pocket stroller, consists of two telescopic tubes in which, one sliding in the other and the handle connected to one tube. The spring with two arms with a V-shape fixed on the inside the inner tube. It was designed and drawn by Giuseppe Perego. The handle can be secured in place with notches that has different levels of elevation (Perego, 1982a). Another design also made by Giuseppe Perego which enables the stroller to be folded from side to side. It is made possible by placing linkages that holds the left and the right frames together as shown in Figure 4(c). The seat has to be made of soft material in order to be folded properly. This design features a rotatable front wheels and lockable back wheels (Perego, 1982b). The stroller designed by Maurice-Claude Duvignacq has an inclinable support for the seat, connected to a frame which can be folded as shown in Figure 5(a). The seat is made of sling-like manner, permanently connected to the frame and it is reversible. The hind legs are able to articulate and be fold to form a flat folded position (Duvignacq, 1983).