From Shaun Walsh
Your article on the use of miniature internal combustion engines as power sources for portable electronic equipment leaves some questions unanswered (19 June, p 26). For example: how do you prevent excessive wear over the lifetime of the power source? Most commonly used lubricants produce some exhaust residues and need to be delivered to the moving parts in some way.
What levels and frequencies of sound do these power sources generate? How large would the silencing system need to be to make the noise level acceptable in a confined space, or in areas containing multiple units? How will the power source be isolated from the electronics to prevent damage to components and connections through vibration?
I doubt there will be a mass market for a laptop that buzzes like a wasp, smells of hot oil and gently massages my lap with its vibrations.
Cheadle, Cheshire, UK
