Hearing aid battery barrier
Embodiments of the invention provide a barrier for protecting hearing aid metal-air battery assemblies from exposure to liquids causing obstruction of a battery air vent. One embodiment provides a barrier configured to be attached to a CIC hearing aid battery having a vent. The barrier has an oxygen permeability configured to allow the diffusion of sufficient oxygen for a battery to meet the power demands of a hearing aid operating in the bony portion of the ear canal over an extended time period. The barrier has a physical property configured to substantially prevent liquid obstruction of at least a portion of the vent on a metal-air battery such as a zinc-air battery. The physical property can be at least one of a hydrophobicity, oleophobocity or surface energy. The barrier can be directly attached to the battery or indirectly via a holder and can encase substantially the entire battery.
1. A battery assembly for a CIC hearing aid, the assembly comprising:
a metal-air battery having a vent; and
a barrier attached to the battery, the barrier having an oxygen permeability configured to allow the diffusion of sufficient oxygen for the battery to meet a power demand of the hearing aid operating in an ear canal over an extended time period, the barrier having a physical property configured to substantially prevent liquid obstruction of at least a portion of the vent,
wherein the barrier encases substantially the entire battery.
2. A battery assembly for a CIC hearing aid, the assembly comprising:
a metal-air battery having a vent;
a barrier attached to the battery, the barrier having an oxygen permeability configured to allow the diffusion of sufficient oxygen for the battery to meet a power demand of the hearing aid operating in an ear canal over an extended time period, the barrier having a physical property configured to substantially prevent liquid obstruction of at least a portion of the vent; and
a barrier holder attached to the battery, wherein the barrier is attached to the battery via the barrier holder, and
wherein the barrier is positioned on the holder to produce a reservoir volume of air between the battery and the barrier, the volume of air allowing operation of the hearing aid for a select period when oxygen ingress into the battery vent decreases below a threshold level.
3. The battery assembly of claim 1 or 2 , wherein the barrier allows the diffusion of sufficient oxygen for the battery to generate a minimum voltage in the range of about 1 to 1.4 volts.
4. The battery assembly of claim 1 or 2 , wherein the barrier is one of a film, a porous material, a porous film, a micro-porous film, a coated micro-porous film, a treated micro porous film or a permselective film.
5. The battery assembly of claim 1 or 2 , wherein the barrier is a porous material which allows diffusion of the sufficient oxygen with a potency of about 2% or greater.
6. The battery assembly of claim 1 or 2 , wherein the barrier is a porous material which has a pore size in the range of about 0.2 to 0.5 microns.
7. The battery assembly of claim 1 or 2 , wherein the barrier is a porous material which has a pores density in the range of about 1 to 5 x 108 pores/cm2.
8. The battery assembly of claim 1 or 2 , wherein the physical property is at least one of hydrophobicity, oleophobicity or surface energy.
9. The battery assembly of claim 1 or 2 , wherein the barrier is directly attached to the vent.
10. The battery assembly of claim 1 or 2 , wherein the barrier includes a first portion positioned proximate the vent and a remainder portion, the remainder portion having a lower oxygen permeability than the first portion.
11. The battery assembly of claim 1 , further comprising:
a barrier holder attached to the battery, wherein the barrier is attached to the battery via the barrier holder.
12. The battery assembly of claim 1 or 2 , wherein the extended time period is about one hour.
13. The battery assembly of claim 1 or 2 , wherein the battery is a zinc-air battery.
14. The battery assembly of claim 1 or 2 , wherein the barrier includes at least a first layer and a second layer.