High Energy Density, Long Life, Betavoltaic Power Cells for Pacemakers and other Implantable Devices

Pacemakers are small devices that help control abnormal heart rhythmscalled arrhythmiawhich can lead to seriouslife threatening conditionsincluding organ damagecardiac arrestand deathIndeedpacemakers are a highly important treatment option for cardiac arrhythmia withimplanted inincludingin the U Sgrowing at an annual rate ofGiven the aging population and increased likelihood of arrhythmia as a person agesthe number of implants is expected to increase in the futureThere are two main limitations associated with the majority of currently marketed pacemakersboth of which are tied to the batteryusable lifetime and device volumeTypical pacemakers need to be replaced everytoyears due to the specified lifetime of their electro chemical batteriesmeaningof pacemaker implantations are replacement devices andof those replacements are battery relatedThis constraint results in significant costup to $per implant in the U Sas well as health risks and inconvenience for the patientPacemaker volume is also an important issue for patients and physiciansCurrent batteries constitute overof the volume of a conventional modelWhile pacemaker size has reduced over timethe current footprint remains visible under the skinand henceless than ideal from a quality of life perspectiveThe goal of this research project is to develop a next generation battery for pacemakers and other medical implants through the development of novel textured silicon carbideSiCbetavoltaics that will provide a more compact and long lived power source for next generation implantsBetavoltaics are micro power sources that produce continuous voltage and current by harvesting betaselectrons produced from isotope decayand converting their energy to electrical power with a semiconductor deviceWidetronix s innovation is embedding an isotope layer around the textured features of a wide bandgap semiconductorBecause of the extremely high energy density of the isotope fuelthis technology has the potential to achieve power densities ten fold greater than existing pacemaker batteries with projected operational lifetimes exceedingyearsThese features will result in definite improvements to the quality of patient care andin the long termreduce the cost of the implantable device over its useful lifetimeOver the course of the NIH Phase I SBIRWidetronix was able to develop a process for securing an isotope layermetal tritideon the surface of our textured SiC devicethereby achieving a consistent beta flux over the active areaThe process led to ax improvement in the energy density of our betavoltaicsThe development under the Phase II will focus on pushing the texturing of the SiC device toward its material limitetching deeper into the SiC while narrowing the featuresthereby allowing the betavoltaic to take full advantage of the extra surface area gained through the texturing processThe goal is to increase the active area density byxfromcmcmtocmcmresulting in an energy density that surpasses existing pacemaker batterieskJ ccand moves us closer to our medical implant partners desired goalThe Phase II aims will involve the investigation and development of process conditions that maximize the exposed betavoltaic surface area while minimizing the device footprinteffectively increasing the devices textured area and thereby maximizing energy density