NeoWax Incubator

Neonatal mortality remains a significant challenge in low-resource healthcare systems, largely due to the high cost, complexity, and maintenance demands of conventional neonatal incubators. In response to these challenges, this project, conducted at the DIPPER Lab, focuses on the design and development of a simplified, reliable, and locally manufacturable neonatal incubator tailored to the needs of Ghanaian hospitals. The objective is to provide stable thermal and humidity control while ensuring safety, affordability, and ease of maintenance.

The incubator design is based on a modular system architecture that integrates controlled heating, passive thermal buffering, humidification, airflow management, and essential alarm functions. Thermal regulation is achieved using incandescent heating elements coupled with a beeswax-based phase change material (PCM). The PCM, housed in an aluminium cartridge, stores and releases heat passively, enabling extended temperature stability and providing resilience during power interruptions. Thermal calculations, including warm-up time, conduction losses, and latent heat storage, were carried out to validate the design and inform heater placement, insulation thickness, and airflow routing.

Humidity control is implemented using a steam-based system consisting of a 1-litre water tray heated by a dedicated electric element. Engineering analysis showed that the humidifier can maintain the target relative humidity range of 55–65% with evaporation power requirements between 31 and 94 W, depending on airflow conditions. The system reaches operational temperature in approximately 23 minutes and can provide several hours of continuous humidification from a single water fill. The humidification unit is physically and thermally isolated from the electronics and heating compartments to improve safety and system reliability.

From a mechanical perspective, the incubator base is partitioned into three distinct compartments: heating, electronics, and humidification. This compartmentalization enhances safety, simplifies servicing, and prevents thermal or moisture interference between subsystems. The infant chamber is constructed from hard-coated polycarbonate due to its impact resistance, optical clarity, low weight, and ease of disinfection. Additional structural elements use ABS, aluminium, and polyurethane insulation. Airflow pathways are designed to promote low-turbulence laminar flow, ensuring uniform distribution of heat and humidity while minimizing drafts that could disturb the infant.

Control and monitoring are handled by an Arduino-based embedded system that regulates temperature and humidity using sensor feedback and PID control algorithms. Multiple temperature sensors and a humidity sensor are strategically positioned within the chamber to ensure accurate environmental monitoring. Safety features include thermal cutoffs, drawer interlock switches that disable heating when accessed, and audible and visual alarms for fault conditions.