Engineering the Impossible: How TDK Helped Corscience Develop the World’s Smallest AED

17-03-26 | Technology & Trends

Designing a portable defibrillator the size of a lunchbox requires solving an engineering paradox: the smaller the high-voltage capacitor, the more energy it leaks over time. For a device that must deliver a decisive shock after months on standby, such energy loss is unacceptable. As the first capacitor prototypes from different manufacturers showed high leakage current, the question became: could this challenge even be solved?

When engineers at Corscience set out to create the world’s smallest automatic external defibrillator (AED), they faced a fundamental engineering paradox: they needed a high-voltage capacitor that was both incredibly compact and remarkably reliable. The challenge would require more than off-the-shelf components; it demanded innovation at the material level. The specifications set by the defibrillation experts from Erlangen were demanding: stable capacitance at 2 kV, delivering the required therapeutic level of stored energy through a biphasic truncated exponential discharge.

The Core Challenge: High Voltage in an Ultra‑Compact Space

But size wasn’t the only constraint. It’s crucial for a defibrillator that the capacitor maintains its charge over extended periods. Any significant leakage current could mean the difference between a functioning defibrillator and a failed rescue attempt. “It is literally vital that the AED is still able to provide the energy for defibrillation after months in standby at different ambient temperatures, like in your car,” explains Manuel Seufert, Team Lead Defibrillation, Shock & Analysis at Corscience.

Why Standard Solutions Reach Their Limits

This requirement created a classic engineering trade-off for TDK: thinner dielectric foils enable smaller capacitor dimensions, but they also increase leakage current. Aluminum electrolytic capacitors require series connections with balancing resistors that continuously discharge the stored energy – unacceptable for this compact AED. Ceramic capacitors face similar limitations. Only film capacitors could meet the demanding voltage and reliability requirements and were the clear choice over ceramic or electrolytic alternatives. To verify this, Corscience developed an automated high-voltage capacitor test bench. The system enables comprehensive evaluation of all relevant capacitor parameters across large sample sizes and under varying temperature conditions. However, initial samples from several manufacturers either exhibited excessive leakage current or exceeded the allowable dimensions. As a result, moving forward required close and in-depth collaboration.

An automated high-voltage capacitor test bench was used for a comprehensive evaluation of all relevant capacitor parameters

Collaboration as Equals

TDK and Corscience sat down to dissect the requirements in detail, combining TDK’s expertise in capacitor manufacturing with Corscience’s extensive experience in defibrillation technology. The second iteration samples were significantly better than comparison types from other manufacturers. “Our collaboration has been a remarkable fusion of innovation and purpose,” notes Anderson Estancovich, the product marketing manager responsible at TDK. “Together, we’ve not only engineered the smallest AED on the market but also redefined what’s possible in medical technology. This makes critical care more accessible, discreet, and patient-friendly than ever before.” The partnership extended beyond just component development. Corscience supported the implementation of a dedicated test bench for future high-voltage capacitors at TDK, enabling real-world simulation and validation of long-term stability.

The Result: A Custom‑Engineered Capacitor for the Next Generation of AEDs

“TDK is a manufacturer with a ‘We can do it’ mentality,” reflects Maciej Postek, Corscience Project Team Lead. “By combining TDK’s expertise in capacitor manufacturing with our knowledge of defibrillation, we were able to develop the perfect capacitor for miniaturized AEDs.” This custom film capacitor combines high energy density and exceptional reliability in an ultra-compact design. It demonstrates what’s possible when two experts come together to create innovative solutions for future generations of highly sophisticated medical devices.