Feasibility Prototypes  
   
     
 

Biodegradable Gardening Tools

Prototyping up a bone shovel and comparing it to its metal counterparts. The shovel did work. However, it was not as easy to use as the thin metal spade. There is also concern that bone would not be able to withstand bending stress as well as a regular shovel.

   
   
     
   
     
 

Bone Touchpad

Testing the piezoelectric properties of the bone in order to determine how effective it would be as a touchpad.

   
     
   
 

 

A sensitive amplifier with a piezoelectric pressure pad was constructed in order to test the bone. The bone was wired into the circuit with small metal contacts. Unfortunately striking the bone did not activate the switch.

 

 
   
 

 

A second prototype was created using a thinner section of bone, with metal foil bonded to it in order to increase contact area and capacitance. This was connected to an oscilloscope to try measure the impulse signal when the bone was impacted. There was no measurable response.

This confirmed the theoretical figures which indicate that bones piezoelectric properties are of the order of 100 times less than those of a regular crystal.

 
     
   
     
   
 

 

Bone Forestry ^

To determine the feasibility of using bone to create a forestry industry in the Western Isles, an expert at Forestry Commission Scotland was contacted. This is the response received from David C Jardine, Forest District Manager, Inverness:

"It is interesting to note that you are investigating the use of waste bovine bone; you are possibly also aware that waste deer bones from deer-culling operations are also incinerated and represent a cost to deer management operations. The suggestion of using the bones as a 'fertiliser' in peat soils is interesting, but one which should be approached with caution as peat soils are now identified as an important carbon sink and adding the bone as a 'fertiliser' has the potential to lead to mineralisation of the soil and could result in significant release of carbon dioxide.

The planting of trees in deep peat soils (least fertile) has been suspended in recent years because of the recognition of their conservation importance and also their role as carbon sinks. However, some planting takes place on shallower peats. Drainage is now usually as much an issue with peat soils as soil fertility. Where planting takes place it is normal to match the choice of tree to the soil fertility and therefore it is not always necessary to apply a fertiliser (although on occasions this is done). Details of the requirements of trees in such soils can be found in standard forestry texts such as Forest Practice (FC Bulletin 7).

While your suggestion of using waste bovine bone to provide a fertiliser for acidic peaty soils is potentialy feasible, I would suggest that other factors driving forestry in peatlands is likely to mean that your suggestion may not have wide applicability. Another area which might be worthwhile considering would be in industrial 'brownfield' sites (eg mineral extraction) where activities can also result in impoverished soils which require fertilisation (as well as action to reduce compaction). However, the suitablity of bones will depend on their mineral content."

 
     
   
     
   
 

The Healing Vase + Electronics Disposal

These concepts where sent to Dr. Mark Hodson (University of Reading) and Dr. Eva Valsami-Jones (Natural History Museum). Both have conducted research into the ability of bone-meal to remove metal contaminates from soil.

 
 
 

Dr. Mark Hodson:

"...The reaction of bonemeal with metals depends on either the metals being in solution and contacting the surface of the bone or the bone dissolving and releasing P that goes on to react with the metal. Either way, with solid bone objects as opposed to ground bone you will not have much surface area so the reaction will only occur very slowly and I suspect not fast enough to have much effect in terrms of regulating metal contamination over the decadal scale. Also with large objects you would have trouble getting a good coverage of them over a site.

I think your second idea, bone housings for electronic devices has more scope as any metals that tried to exit the housing would presumably be in solution and would therefore come into contact with the bone housing and, potentially, react with it.

A third possibility is if your whole bone objects were put together to form a porous wall to remediate contaminated water that flowed through cracks in the bone - you'd have good contact with the bone. Eva has, I think, more recently been looking at such reactive permeable barrier technology with bone meal and may have views on this...."

Dr Eva Valsami-Jones:

"....I agree with all Mark's comments. Although in my opinion, whole bone is as reactive as bone meal, and has a lot of porosity so high surface area, there's still the issue of the need for intimate contact with a solution carrying the contaminants for the method to work. I have to say that I dont see how a housing made of bone would work..."

 

 
   
     
 

Chosen Concept

Bone product housings which prevent heavy metal contamination.

 
 
     
 
Copyright Andrew Ross 2008