Multifunctional flexible piezoelectrics for wearable medical devices

In healthcare technologies intelligent wearable devices provide an added value to diagnosis, treatment, patient monitoring and prevention. The global market for medical wearable devices is expected to reach $12.1 billion by 2021.

Diabetes is one of the most common chronic endocrine conditions that can develop at any stage of life and its incidence is increasing rapidly. There are currently 415 million people worldwide with diabetes and this number is expected to grow up to 642 million in 2040. Diabetic peripheral neuropathy is a common complication, where the loss of sensation caused by nerve damage can make it difficult for patients to feel when their foot is at risk of skin breakdown, which can result in foot ulcers forming. These ulcers can fail to heal and become infected over time; around 30% of patients with a diabetic foot ulcer may be at risk of lower limb amputation. Current best practice recommends patients perform daily monitoring of their feet supported by regular physical examination by trained specialists, which is time consuming.

Here we propose development of a novel self-powered wearable multifunctional sensing device that monitors the patient’s posture. Whenever the pressure sensing inserts detect clinically dangerous foot pressure, a light signal and an audio alert is transmitted prompting the device user to offload the pressure from a particular region of their foot.

The multifunctional device will be composed of layers of screen-printed functional ceramic inks on a flexible polymer substrate. A phosphor layer generates electroluminescent (EL) light and a piezoelectric layer harvests mechanical energy and convert it into EL light for feedback. A pyroelectric layer harvests thermal energy and converts that to electrical energy. Lead-free ferroelectric ceramics will be printed different phosphors such as ZnS and ZnS:Cu will be fabricated to achieve optimum and uniform light emission. Coupling of the phosphor, piezoelectric and pyroelectric materials will result in a piezo-pyro-electro-luminescence device with light emission powered by energy harvesting of the external mechanical and thermal energy.

The project is in collaboration with DST Innovations, an expert company in lightweight, low powered and flexible lightings. The focus of DST is developing energy efficient and environmentally safe technologies that can replace those used in today’s electronic products. The company will support the project by offering technical knowledge.

The PhD candidate will:
• Formulate and test the printability and performance of lead-free piezoelectric inks (BT, KNN-based) and phosphor inks (ZnS etc)
• Formulate and test the inks for optimum electrode structure
• Fabricate multilayer devices using screen printing. Piezoelectric and phosphor layers will be printed individually and in combination, with and without electrodes.
• Characterise the physical and electromechanical properties using impedance spectroscopy, piezoelectric, pyroelectric, ferroelectric, electroluminescence and surface roughness analysis
• Develop and test the self-powered multifunctional wearable piezoelectric device

Informal enquiries should be addressed to Dr Hamideh Khanbareh ([Email Address Removed])

Candidate:
The successful applicant will ideally have graduated (or be due to graduate) with an undergraduate Masters first class degree or MSc distinction (or overseas equivalent) in materials//chemical/mechanical/electrical engineering, physics or similar disciplines.

English language requirements must be met at the time of application to be considered for funding.

Application:
Formal applications should be made via the University of Bath’s online application form for a PhD in Mechanical Engineering. Please ensure you state the full project title and lead supervisor name.

https://samis.bath.ac.uk/urd/sits.urd/run/siw_ipp_lgn.login?process=siw_ipp_app&code1=RDUME-FP01&code2=0014

Anticipated start date: 20 January 2020