Associate Professor Lee Seok Woo, from NTU, in Singapore, tells us how a Tom Cruise film inspired him to create a battery, powered by tears, that's so small it could be fitted to a contact lens. Ben Derico reports from San Francisco on why Chatbot detectors are mistakenly accusing people for whom English is a second language of cheating in exams. Analyst Ben Wood, from CCS Insight, brings us up to speed on Apple's latest product plans. And journalist Jack Thompson guides us through the farming revolution in Senegal, being powered by WhatsApp voicenotes.