Interactive Delivery Cart

Designers: Anumeha Goel, Linda Qu, Karen Schroeder, Alaina Pleatman

Client Coordinator: Susan Parker, PT, Durham County Schools

Supervising Professor: Dr. Larry Bohs



Elementary school students with disabilities often have difficulty interacting with teachers and other children due to cognitive and physical limitations.  The goal of this project was to design a delivery cart that serves as both a learning and therapeutic tool, providing a safe, customized, and fun device from which the students learn to assume responsibility and practice essential skills.  Students make deliveries of items such as newspapers to other people and classrooms throughout the school.  Key features include color-coded bins, left-right signaling, braking, and handle height adjustment.  The delivery cart is a unique resource in a special needs classroom and equips children to integrate into work and social environments as they grow older.


The delivery cart is a unique therapeutic device for elementary school students with disabilities, helping to promote motor skills as well as work ethic and responsibility.  It is accessible to students of a range of ages and physical abilities. The design is safe, adaptable, and interactive, allowing teachers and therapists to gradually add accessories as students develop their cognitive and motor skills. Our supervisor commented, “Because the device was made for several targeted children it will certainly benefit them, but I am very pleased that it can benefit multiple users, even in the future. It’s wonderful for teaching a multi-step task, in that some steps can be added or eliminated commensurate with the child’s skill level.”


The main components of the Interactive Delivery Cart (Figure 1) are a height-adjustable handle, hand brakes, dashboard for holding a communication device and task cards, color-coded bins, turn signals, a base for additional storage, tip-stoppers and wheelchair adaptation accessories.  The cart was modified from a commercial shopping cart.

The custom-bent handlebar adjusts in height for use by both children and adults. Knob screws on either side loosen and tighten the vertical supports to slide the handle to the desired position.  Tennis grip tape allows for a comfortable grasp.

Hand brakes, modified from commercial walker brakes, allow users to slow themselves down when moving on uneven surfaces or downhill.  The brake handles are secured to the left and right undersides of the handlebar, and are squeezed to engage the rubber-coated brake friction levers, which are mounted near each rear wheel.

The dashboard is constructed of 0.125” thick acrylic and features a ledge to hold the student’s communication device. A Velcro strip directly above the communication device displays task cards corresponding to the color-coded individual bins; these cards may be selected from the task card binder. The dashboard is securely supported on the back wall of the cart’s large basket.

Color-coded bins, lined with colored felt, allow children to learn and distinguish between various colors in association with the delivery tasks.  The bins are easily removed according to the teacher or supervisor’s preference. Red vinyl covering the cart sides makes the design more aesthetically pleasing and smoothes sharp corners.

The base is constructed from 0.25” clear acrylic and is useful for additional or bulky item storage. The front edge curves upward as a ledge to prevent items stored on the base from falling.  Tip-stoppers attached to the front corners of the cart frame normally ride 1/8” above the ground, but make contact if the cart is tipped laterally.

To help reinforce the concept of left and right, a custom circuit voices a recorded message, “Turning left” or “Turning Right”, as well as lighting one of two turn signals as the cart makes a turn.  The circuit detects the rotation of the front center wheel with reed relays and a magnet using an ATTiny2313 microcontroller. It is powered by a 9V battery.  Figure 2 shows a student and therapist using the cart.  Replacement cost is about $240.

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