Sometimes robot-like mindfulness can come about because we are not actually paying attention to the changes in the moment - we are just flowing with things. So becoming more aware of how things are changing can bring up the investigation more and this can help to break out of the excess concentration that sometimes happens when we become robot-like.
For example, paying more attention to impermanence. Say for instance, in walking meditation, sometimes the focus may be more on tranquility rather than insight, in that we are just flowing into the footsteps and can get a lot of calm arising in the mind. We can become trance-like with glassy staring eyes that is not even aware of what you're stepping on. At that time it may help to broaden the awareness by becoming aware of the contacts that arise at the senses instead of focusing so much on the footsteps. Become more aware of how things are arising towards the senses and try to note the feeling, noting how they are arising and passing. This is focusing more on insight of the impermanence from the senses, focusing more on the fourth Foundation of Mindfulness. Investigating the contact with the senses, their objects and the characteristics of things.
Sometimes the robot-like mindfulness can mean you are just flowing too much into the tranquility that mindfulness can often bring about because when we are not thinking and are present it can be very calming. So bringing up the investigation enlightenment factor can be very helpful at these times and as I said in the walking, it's broadening out to watching the contacts at the sense doors, investigating into impermanence more. It may actually help to change the awareness, if we are sitting, to a Compassion/Lovingkindness meditation to strengthen the compassion so that we are opening more to Dukkha as sometimes robot mindfulness indicates indifference.
Sometimes we may be doing things too slowly, so quickening up the pace helps to break out of this robot-like mindfulness where we are so minute with the activities, we lose awareness of how these activities relate to the future or the past or the environment - i.e. lack of clear comprehension. Broadening our awareness is often helpful. There is sometimes too much tranquility that is overpowering the mindfulness so that the concentration has become excessive. There may be mindfulness but the concentration has become too dominant. So by increasing the clear comprehension factor, by investigating into the characteristics of things, helps to make our mindfulness sharper. If we are watching the breathing, pay more attention to the changes in the breathing and how the breathing is affected by the mind states. This is very helpful. These are just a few ways to help us break out of that robot-like mindfulness.
For the robot-like mindfulness that is coming from a sense of indifference, stimulating what is called, Samvega can help, a sense of urgency. Reflecting on death can help so that we are not just flowing into the pleasantness of mindfulness. It helps us be more alert.